This PR introduces MSAL as a dependency and switches our supported bot
authentication to use it. It also includes support for User Managed
Identity support and FIC such that we don't need to provide custom code
to do that anymore as we had previously suggested. Instead, we can do
that simply by the environment variables.

| CLIENT_ID | CLIENT_SECRET | MANAGED_IDENTITY_CLIENT_ID | Output |
|-|-|-|-|
| not_set | | | No-Auth |
| set | set | | SecretsAuth |
| set | not_set | | User Managed Identity Auth |
| set | not_set | set (same as CLIENT_ID) | User Managed Identity Auth |
| set | not_set | set (diff from CLIENT_ID) | FIC (user managed
identity) |
| set | not_set | "system" | FIC (system identity) |

Changes to note:
1. We are now no longer _proactively_ refreshing tokens. Instead, we put
the token fetcher inside the token resolver logic for the client. This
ends up being a call to `tokenManager.getBotToken`.
2. This fixes a bug where proactive scenarios were going to fail because
we weren't refreshing the token for them. For reactive scenarios, we
refresh the token when the request comes in, so it was fine.
3. We are deprecating the `id` and `name` fields because those used to
depend on the token being present. Now that we are not proactively
fetching the token, those are not as useful (or reliable). For now, I
have chosen to simply use the value from the manifest to populate them.
I don't think these fields were that useful anyway, so opting to
deprecate.
4. Removes graphToken from being injected into plugins. Plugins weren't
using it, and we want to remove tight dependency on graph package.
















#### PR Dependency Tree


* **PR #387** 👈
* Merged #388, #389, #392

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