feat: [SIW-1591] Add 409 handling with custom exception for wallet provider

[LazyAfternoons]

List of Changes

• Update the wallet-provider.yaml specs due to changes in how the errors are mapped for certain endpoints like /token and /wallet-instance;
• Create custom exceptions which are thrown when an error related to the integrity checks for /token and /wallet-instances fails, returning a 409 HTTP code;
• Map these errors in their relative flows step for registering a wallet instance and obtaining an attestation.

Motivation and Context

This changes allows the consumer app to receive a custom error when an integrity check fails, thus allowing a specific text copy to be shown to the user.

How Has This Been Tested?

• Open the example app and login;
• Start a proxy like Proxyman;
• Try to register a wallet instance and obtain an attestation, everything should work just as before;
• Manually map the result of /token and /wallet-instances to 409 Conflict;
• Try again to register a wallet instance and obtain an attestation. An error should occur. Check in the debug menu that the error is the one supposed to be thrown in this specific case.

Screenshots (if appropriate):

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[grausof]

perfect

[grausof]

Remember to increase the package version.

[LazyAfternoons]

Remember to increase the package version.

Usually I bump the versioni in a different commit, I prefer to do so