Fixes after review

[KyrylR]

1. Added check for the current index in ensure_correct_change_at_index. Fixes Always check current index #4
2. Simplified match token_branch in funding_path. Fixes Simplify match token_branch in funding_path. #3
3. Added link to Use input asset to determine option covenent type issue. Fixes Use input asset to determine option covenent type #2
4. Reduced contract parameters. Fixes Reduce Contract Parameters #5

New run:

```bash
cargo run -p cli -- basic split-native \
  --broadcast \
  --utxo 07ecfc3fb98db1693b2721c5efeea1a0bb348b4bc6ff4ef57526e9d5d8e4867f:3 \
  --first-to-address tex1pxztvg542emmh9h8txga43jcltt4uhphpt79lylqmlwrafzvcferq2qpdg9 \
  --first-sats 2000 \
  --second-to-address tex1pxztvg542emmh9h8txga43jcltt4uhphpt79lylqmlwrafzvcferq2qpdg9 \
  --second-sats 85140 \
  --fee-sats 50 \
  --account-index 0

Done: https://liquid.network/testnet/tx/0ebb7bbe4d2bd72d5bf12e5d65cf5e8816a821c7d9600bd6c8bf3a6d80b9f0ee
Done 2 (cancellation test): https://liquid.network/testnet/tx/0fb896c5620f9415172e02e48c98a3b27380398fe7af8d9d8c3ba974b55607dd

cargo run -p cli -- options creation-option \
  --broadcast \
  --first-fee-utxo 0fb896c5620f9415172e02e48c98a3b27380398fe7af8d9d8c3ba974b55607dd:0 \
  --second-fee-utxo 0fb896c5620f9415172e02e48c98a3b27380398fe7af8d9d8c3ba974b55607dd:1 \
  --start-time 1761821609 \
  --expiry-time 1761821609 \
  --collateral-per-contract 20 \
  --settlement-per-contract 5 \
  --settlement-asset-id-hex-be 38fca2d939696061a8f76d4e6b5eecd54e3b4221c846f24a6b279e79952850a5 \
  --account-index 0 \
  --fee-amount 100

options_taproot_pubkey_gen: 763d23b0bd02337bb267fa1282ae129cef814833e1456644afa3053b9031051f:027f8873a023e321ea3df56a0dcb098479030ee0be868f0f5fe6fba1da8d0bb9f9:tex1pt355pzatlmcxtuasd2rynd0wvmxh8l9g8y8kwk5fv7p0dckszd3sfwjnpv
Done: https://liquid.network/testnet/tx/fe3e22444adb80b5da75aa44cbf4ab52c6b3a6ecbfd9a010e2bc9bb81dfa2a26

options_taproot_pubkey_gen: 7efe3e23414653a1cf58cee8fed04113491ce002e225f28478733548dc51ec66:02b0a4727eefe4cae1748d20cc361b718d06b1bb5347b323ba1d71a617ee483933:tex1pahzvqxjle9zvdzf2gw3q86ps32hxet5tuy0zwdtys7zjg9s529jsf7ul2z
Done 2 (cancellation test): https://liquid.network/testnet/tx/6ca00f7cab1db9e7ed09e9fbc446c4fcc83074b67d83faa15a02510183793b02

cargo run -p cli -- options funding-option \
  --broadcast \
  --option-asset-utxo 6ca00f7cab1db9e7ed09e9fbc446c4fcc83074b67d83faa15a02510183793b02:0 \
  --grantor-asset-utxo 6ca00f7cab1db9e7ed09e9fbc446c4fcc83074b67d83faa15a02510183793b02:1 \
  --collateral-and-fee-utxo 6ca00f7cab1db9e7ed09e9fbc446c4fcc83074b67d83faa15a02510183793b02:2 \
  --option-taproot-pubkey-gen 7efe3e23414653a1cf58cee8fed04113491ce002e225f28478733548dc51ec66:02b0a4727eefe4cae1748d20cc361b718d06b1bb5347b323ba1d71a617ee483933:tex1pahzvqxjle9zvdzf2gw3q86ps32hxet5tuy0zwdtys7zjg9s529jsf7ul2z \
  --collateral-amount 2000 \
  --account-index 0 \
  --fee-amount 205

Done: https://liquid.network/testnet/tx/c71f1901a96d2f843eca628e595f97649a080668229d8800a2ca094051b77e5d
Done 2 (cancellation test): https://liquid.network/testnet/tx/9480d87d08f6dc8c4213548d159c40d5f93f5068e59c06e174e21a7d50a75dd2

cargo run -p cli -- options exercise-option \
  --broadcast \
  --collateral-utxo c71f1901a96d2f843eca628e595f97649a080668229d8800a2ca094051b77e5d:2 \
  --option-asset-utxo c71f1901a96d2f843eca628e595f97649a080668229d8800a2ca094051b77e5d:3 \
  --asset-utxo e8b5cc998d9fcc484cd6e0cf3768ca4dbd7376d8839f18599f9f000c1b9e0bd6:0 \
  --fee-utxo c71f1901a96d2f843eca628e595f97649a080668229d8800a2ca094051b77e5d:5 \
  --option-taproot-pubkey-gen 763d23b0bd02337bb267fa1282ae129cef814833e1456644afa3053b9031051f:027f8873a023e321ea3df56a0dcb098479030ee0be868f0f5fe6fba1da8d0bb9f9:tex1pt355pzatlmcxtuasd2rynd0wvmxh8l9g8y8kwk5fv7p0dckszd3sfwjnpv \
  --amount-to-burn 75 \
  --fee-amount 165 \
  --account-index 0

Done: https://liquid.network/testnet/tx/ceea050ab1da532ce4e60241eb948cc4a2ffaec8a320c494dc460ed75b376aae

cargo run -p cli -- options settlement-option \
  --broadcast \
  --settlement-asset-utxo ceea050ab1da532ce4e60241eb948cc4a2ffaec8a320c494dc460ed75b376aae:2 \
  --grantor-asset-utxo c71f1901a96d2f843eca628e595f97649a080668229d8800a2ca094051b77e5d:4 \
  --fee-utxo ceea050ab1da532ce4e60241eb948cc4a2ffaec8a320c494dc460ed75b376aae:5 \
  --option-taproot-pubkey-gen 763d23b0bd02337bb267fa1282ae129cef814833e1456644afa3053b9031051f:027f8873a023e321ea3df56a0dcb098479030ee0be868f0f5fe6fba1da8d0bb9f9:tex1pt355pzatlmcxtuasd2rynd0wvmxh8l9g8y8kwk5fv7p0dckszd3sfwjnpv \
  --grantor-token-amount-to-burn 25 \
  --fee-amount 150 \
  --account-index 0

Done: https://liquid.network/testnet/tx/4e07ca1481d6e8b39c29c89e784f436333e50596288af5f65f9a7151c5b8e19c

cargo run -p cli -- options expiry-option \
  --collateral-utxo ceea050ab1da532ce4e60241eb948cc4a2ffaec8a320c494dc460ed75b376aae:0 \
  --grantor-asset-utxo 4e07ca1481d6e8b39c29c89e784f436333e50596288af5f65f9a7151c5b8e19c:3 \
  --fee-utxo 4e07ca1481d6e8b39c29c89e784f436333e50596288af5f65f9a7151c5b8e19c:4 \
  --option-taproot-pubkey-gen 763d23b0bd02337bb267fa1282ae129cef814833e1456644afa3053b9031051f:027f8873a023e321ea3df56a0dcb098479030ee0be868f0f5fe6fba1da8d0bb9f9:tex1pt355pzatlmcxtuasd2rynd0wvmxh8l9g8y8kwk5fv7p0dckszd3sfwjnpv \
  --grantor-token-amount-to-burn 25 \
  --fee-amount 150 \
  --account-index 0 \
  --broadcast 

Done: https://liquid.network/testnet/tx/07ecfc3fb98db1693b2721c5efeea1a0bb348b4bc6ff4ef57526e9d5d8e4867f

cargo run -p cli -- options cancellation-option \
  --collateral-utxo 9480d87d08f6dc8c4213548d159c40d5f93f5068e59c06e174e21a7d50a75dd2:2 \
  --option-asset-utxo 9480d87d08f6dc8c4213548d159c40d5f93f5068e59c06e174e21a7d50a75dd2:3 \
  --grantor-asset-utxo 9480d87d08f6dc8c4213548d159c40d5f93f5068e59c06e174e21a7d50a75dd2:4 \
  --fee-utxo 9480d87d08f6dc8c4213548d159c40d5f93f5068e59c06e174e21a7d50a75dd2:5 \
  --option-taproot-pubkey-gen 7efe3e23414653a1cf58cee8fed04113491ce002e225f28478733548dc51ec66:02b0a4727eefe4cae1748d20cc361b718d06b1bb5347b323ba1d71a617ee483933:tex1pahzvqxjle9zvdzf2gw3q86ps32hxet5tuy0zwdtys7zjg9s529jsf7ul2z \
  --amount-to-burn 100 \
  --fee-amount 150 \
  --account-index 0 \
  --broadcast

Done: https://liquid.network/testnet/tx/86c10905302c54812af0bbcae917b6458a1108ef0292634eaa1dbb9340aa870f

[roconnor-blockstream]

@apoelstra should also review.