feat: adding tos to mint

[nodlAndHodl]

Description

Adding tos field to MintInfo (nut06.rs) and updated the cdk-sqlite migration in the wallet.

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Notes to the reviewers

I saw the not in the NUT-06 reference about using tos_url but didn't see any strong push to use that over a string tos. In my opinion, a client that is implementing this could use a uri parser to evaluate if the `tos is a uri or if it's just text.

The sqlx migration is in place for the cdk-sqlite crate. Might be nice at some point to have a set of integration tests similar to the test_swap_send but for the cdk-sqlite

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Suggested CHANGELOG Updates

CHANGED

ADDED

Added a tos field type of String to the MintInfostruct.

REMOVED

FIXED

Update the comment NIP-06 to read NUT-06

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Checklist

• I followed the code style guidelines
• I ran just final-check before committing

[thesimplekid]

Thanks for this PR LGTM we'll just have to wait for consensus on the nut.