SPL Transfer Hook Interface v0.4.1

New instruction added to the SPL Transfer Hook Interface for updating the list of additional account metas required for a transfer.

/// Updates the extra account metas on an account by overwriting the
/// existing list.
///
/// Accounts expected by this instruction:
///
///   0. `[w]` Account with extra account metas
///   1. `[]` Mint
///   2. `[s]` Mint authority
UpdateExtraAccountMetaList {
    /// The new list of `ExtraAccountMetas` to overwrite the existing entry
    /// in the account.
    extra_account_metas: Vec<ExtraAccountMeta>,
},

Previously, there was no such instruction for updating this list, and it would have to be implemented separately by anyone seeking to do such an update. Now it has first-class support in the interface.

Shout out to @tonton-sol for the PR! #5894