Permissioned burn extension

[Szegoo]

This PR implements a permissioned-burn extension as described in #772

Summary

Introduces the PermissionedBurn mint extension, enabling both burn and burn_checked operations that require approval from a designated authority configured during mint initialization.

When this extension is enabled, standard burn and burn_checked instructions are disallowed for the mint. This PR does not modify the existing behavior of regular burns for mints that do not use the extension.

TODO:

• Tests covering the new extension
• Add the extension to CLI
• Add the extension to js client

Closes #772

[Szegoo]

@joncinque Would really appreciate a quick review, just to confirm that I’m moving in the right direction before adding the tests.

[joncinque]

Thanks for your contribution! This is definitely on the right track, but I think we'll need a bit more functionality. Let me know what you think!

[Szegoo]

@joncinque I would need a bit of guidance on adding tests for the permissioned burn.

I see tests in rust-legacy and js-legacy, but since they’re marked legacy I’m unsure of the current convention. Where should new tests go?

[joncinque]

I see tests in rust-legacy and js-legacy, but since they’re marked legacy I’m unsure of the current convention. Where should new tests go?

Thankfully, legacy doesn't mean deprecated, so please add the tests to the rust-legacy client 😄

This is on the right track, keep it up! Let me know if you need anything else on my side, apologies for the slowness on the re-review

[Szegoo]

@joncinque Everything should be resolved now :)

[joncinque]

This looks really good! Mostly nits, and a question about what to do if the authority is set to None.

We'll eventually need to add the ability to specify a burn authority in the CLI and rust-legacy clients, but that can happen later

[joncinque]

I kicked off CI, and there are a few little things to fix:

• reformat the rust code with make format-rust
• fix clippy issues -- you can check individual packages with make clippy-program, make clippy-interface, make clippy-clients-rust-legacy, and make clippy-clients-cli
• add permissioned as a word in the dictionary for spellcheck at https://github.com/solana-program/token-2022/blob/main/scripts/solana.dic, and check that make spellcheck passes
• generate the clients with make generate-clients and commit the results
• it looks like there's a legitimate test failure in the program from multiple borrows, so be sure to fix that up

Let me know if you need any help with these pieces 😄