Merge MFA into dev

[kozabrada123]

Continuation of #521

TODOs

• Mock the mfa tests with the httptest crate, the original reason why mfa wasn't merged into dev
• Add new user mfa routes (along with testing them):
  • Enable TOTP MFA
  • Disable TOTP MFA
  • Enable SMS MFA
  • Disable SMS MFA
  • Get WebAuthn Authenticators
  • Create WebAuthn Authenticator
  • Modify WebAuthn Authenticator
  • Delete WebAuthn Authenticator
  • Send Backup Codes Challenge
  • Get Backup Codes
• Send the mfa token in the requests that need it
• Test that the implementation fully works, and see how ergonomic its api is to use

Original description

Here is my suggested implementation of MFA #40

Features

• Adds the required Request/Response structs for the MFA implementation.
• Adds a new MfaRequired error on ChorusError.
• Adds complete_mfa_challenge which calls the endpoint to verify MFA.

Refactors

• Removes struct TotpSchema.
• Changes ChorusUser struct definition, the user field type is wrapped with Option so there is an exact way to know when it is authenticated. The shell function has also been changed accordingly.
• Changes current API endpoints according to the changes made to ChorusUser.

Notes

• The following changes are a foundation for a future full MFA implementation throughout all endpoints that require it, as some endpoints are not implemented yet.
• For unauthenticated endpoints that require MFA verification, a user of the library (Chorus) will have access to the required functionalities to manually implement such verification.

New changes:

• Updated mfa branch with the latest dev commits
• The original Option on the object field in ChorusUser has been removed, to make the api more ergonomic. If we aim to re-do how ratelimited requests work, adding the Option for a few versions and then removing it again at some point is quite annoying from an api pov. shell was (until now, with one unauthenticated mfa endpoint) called only when creating a new (authenticated)ChorusUser, which imo justified its calls to User::default and UserSettings::default as they were overridden soon after. A true solution for this issue would be to allow the Instance to perform unauthenticated yet still ratelimited requests, which likely means a rework of the ratelimiter logic.
• A new method was added, ChorusUser::update_with_login_data, which replaces the last couple of lines (gateway identifying, fetching user object and user settings) for each login implementation, as that was just duplicated code
• The mfa login logic has been updated to behave more like the other login functions
• The AuthenticatorType enum, from the Ready payload has been moved to the mfa types and renamed to MfaAuthenticatorType. Another similar type MfaAuthenticationType was added, which covers authenticator types along with using a password or backup code.
• A new api was added to MfaToken and ChorusRequest (1927ed8), which allows adding the mfa token to requests that need it (if we have obtained one)
• As a result of this, MfaToken has been feature locked to the Client feature (825e0ed)
• Added httptest as a dev-dependency on non wasm targets
• Added a function to setup httptest's server with common routes needed for testing chorus
• Added a function to setup TestBundle on an httptest server
• Updated mfa tests to work with a mocked server
• Added the new user mfa routes, along with tests for them