TokenClient burn / burn_from functions do not document panic cases

[jsmaxi]

The burn and burn_from functions in TokenClient lack documentation about when they will panic. I believe, these functions will panic and revert the tx if the account has insufficient balance, if authorization is missing, or if the amount is invalid (<=0).

Currently the documentation only describes the basic functionality but does not mention any panic/error conditions.

The same may apply to some other token client functions.

https://github.com/stellar/rs-soroban-sdk/blob/07384526b8b052905a27c145a9c972922739106f/soroban-sdk/src/token.rs

https://docs.rs/soroban-sdk/latest/soroban_sdk/token/struct.TokenClient.html

[leighmcculloch]

The SEP-41 Token function errors are not documented because they can be very much implementation specific. In the classic protocol error cases were specified and over time it made it difficult to maintain so we corrected, maybe over corrected, the other way.

It might be reasonable to document some possible cases but with a disclaimer that it is ultimately implementation specific and the SEP doesn't specify or limit the cases.

[leighmcculloch]

What we're really discussing here is whether SEP-41 is underspecified, because the token clients in this SDK just implement a client to interface with SEP-41 implementations and so just documents what SEP-41 states. I'm transferring this to the discussions forum where we can continue to discuss if SEP-41 is underspecified or not.