refactor(oidc): Start replacing mas-oidc-client with oauth2

[zecakeh]

This makes use of the oauth2 crate for the authorization code grant and the refresh token grant.

There is still the token revocation that can use oauth2, but it requires changes in the HTTP client so it will be done separately. And the remaining parts (account management URL, fallback discovery, registration) will need to be included in the SDK to get rid of mas-oidc-client.

[codecov]

Codecov Report

Attention: Patch coverage is 91.02564% with 7 lines in your changes missing coverage. Please review.

Project coverage is 86.28%. Comparing base (6c9b1ef) to head (6b004bc).

Files with missing lines	Patch %	Lines
crates/matrix-sdk/src/authentication/oidc/error.rs	62.50%	3 Missing ⚠️
crates/matrix-sdk/src/authentication/oidc/mod.rs	93.75%	3 Missing ⚠️
...matrix-sdk/src/authentication/oidc/qrcode/login.rs	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4761      +/-   ##
==========================================
+ Coverage   86.26%   86.28%   +0.01%     
==========================================
  Files         290      291       +1     
  Lines       34286    34291       +5     
==========================================
+ Hits        29578    29587       +9     
+ Misses       4708     4704       -4     

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