chore(docs): Update implementation references in token contract tutor…

…ial (AztecProtocol#3626)

This PR includes some edits to the token contract tutorial, to keep the
text consistent with the referenced source code.

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docs/docs/dev_docs/tutorials/writing_token_contract.md

@@ -210,7 +210,7 @@ Just below the contract definition, add the following imports:
 
 #include_code imports /yarn-project/noir-contracts/src/contracts/token_contract/src/main.nr rust
 
-We are importing the Option type, items from the `value_note` library to help manage private value storage, note utilities, context (for managing private and public execution contexts), `state_vars` for helping manage state, `types` for data manipulation and `oracle` for help passing data from the private to public execution context. We also import the `auth` [library](https://github.com/AztecProtocol/aztec-packages/blob/#include_aztec_version/yarn-project/aztec-nr/aztec/src/auth.nr) to handle token authorizations from [Account Contracts](../../concepts/foundation/accounts/main). Check out the Account Contract with AuthWitness [here](https://github.com/AztecProtocol/aztec-packages/blob/#include_aztec_version/yarn-project/noir-contracts/src/contracts/schnorr_single_key_account_contract/src/main.nr).
+We are importing the Option type, note utilities, context (for managing private and public execution contexts), `state_vars` for helping manage state, `compute_selector` for helping with calling public functions from private functions, and `types` for data manipulation. We also import the `authwit` [library](https://github.com/AztecProtocol/aztec-packages/blob/#include_aztec_version/yarn-project/aztec-nr/aztec/src/auth.nr) to handle token authorizations from [Account Contracts](../../concepts/foundation/accounts/main). Check out the Account Contract with AuthWitness [here](https://github.com/AztecProtocol/aztec-packages/blob/#include_aztec_version/yarn-project/noir-contracts/src/contracts/schnorr_single_key_account_contract/src/main.nr).
 
 [SafeU120](https://github.com/AztecProtocol/aztec-packages/blob/#include_aztec_version/yarn-project/aztec-nr/safe-math/src/safe_u120.nr) is a library to do safe math operations on unsigned integers that protects against overflows and underflows.
 
@@ -309,7 +309,7 @@ First, storage is initialized. Then it checks whether the calling contract (`con
 
 ##### Authorizing token spends
 
-If the `msg_sender` is **NOT** the same as the account to debit from, the function checks that the account has authorized the `msg_sender` contract to debit tokens on its behalf. This check is done by computing the function selector that needs to be authorized (in this case, the `shield` function), computing the hash of the message that the account contract has approved. This is a hash of the contract that is approved to spend (`context.msg_sender`), the token contract that can be spent from (`context.this_address()`), the `selector`, the account to spend from (`from.address`), the `amount`, the `secret_hash` and a `nonce` to prevent multiple spends. This hash is passed to `assert_valid_public_message_for` to ensure that the Account Contract has approved tokens to be spent on it's behalf.
+If the `msg_sender` is **NOT** the same as the account to debit from, the function checks that the account has authorized the `msg_sender` contract to debit tokens on its behalf. This check is done by computing the function selector that needs to be authorized (in this case, the `shield` function), computing the hash of the message that the account contract has approved. This is a hash of the contract that is approved to spend (`context.msg_sender`), the token contract that can be spent from (`context.this_address()`), the `selector`, the account to spend from (`from.address`), the `amount`, the `secret_hash` and a `nonce` to prevent multiple spends. This hash is passed to `assert_current_call_valid_authwit_public` to ensure that the Account Contract has approved tokens to be spent on it's behalf.
 
 If the `msg_sender` is the same as the account to debit tokens from, the authorization check is bypassed and the function proceeds to update the account's `public_balance` and adds a new `TransparentNote` to the `pending_shields`.
 
@@ -360,7 +360,7 @@ The function returns `1` to indicate successful execution.
 
 This private function enables un-shielding of private `ValueNote`s stored in `balances` to any Aztec account's `public_balance`.
 
-After initializing storage, the function checks that the `msg_sender` is authorized to spend tokens. See [the Authorizing token spends section](#authorizing-token-spends) above for more detail--the only difference being that `assert_valid_message_for` is modified to work specifically in the private context. After the authorization check, the sender's private balance is decreased using the `decrement` helper function for the `value_note` library. Then it stages a public function call on this contract ([`_increase_public_balance`](#_increase_public_balance)) to be executed in the [public execution phase](#execution-contexts) of transaction execution. `_increase_public_balance` is marked as an `internal` function, so can only be called by this token contract.
+After initializing storage, the function checks that the `msg_sender` is authorized to spend tokens. See [the Authorizing token spends section](#authorizing-token-spends) above for more detail--the only difference being that `assert_current_call_valid_authwit` is modified to work specifically in the private context. After the authorization check, the sender's private balance is decreased using the `decrement` helper function for the `value_note` library. Then it stages a public function call on this contract ([`_increase_public_balance`](#_increase_public_balance)) to be executed in the [public execution phase](#execution-contexts) of transaction execution. `_increase_public_balance` is marked as an `internal` function, so can only be called by this token contract.
 
 The function returns `1` to indicate successful execution.
 
@@ -370,7 +370,7 @@ The function returns `1` to indicate successful execution.
 
 This private function enables private token transfers between Aztec accounts.
 
-After initializing storage, the function checks that the `msg_sender` is authorized to spend tokens. See [the Authorizing token spends section](#authorizing-token-spends) above for more detail--the only difference being that `assert_valid_message_for` is modified to work specifically in the private context. After authorization, the function gets the current balances for the sender and recipient and decrements and increments them, respectively, using the `value_note` helper functions.
+After initializing storage, the function checks that the `msg_sender` is authorized to spend tokens. See [the Authorizing token spends section](#authorizing-token-spends) above for more detail--the only difference being that `assert_current_call_valid_authwit` is modified to work specifically in the private context. After authorization, the function gets the current balances for the sender and recipient and decrements and increments them, respectively, using the `value_note` helper functions.
 
 #include_code transfer /yarn-project/noir-contracts/src/contracts/token_contract/src/main.nr rust