feat(dart-dio): add methods to remove auth tokens in api client

[nopjar]

There is currently no way to easily remove a previously set auth token. Adding these methods will provide a convenient way to 'revoke' tokens.

Design-Choice:
Adding those new methods is a better alternative as just making the values of existing methods nullable, as e.g. #setBasicAuth(String, String, String) has two value parameters, which then would have to be checked for nullability and special handling would be required if only one value is null. This would result in a less clear API. By adding new methods following the naming #removeXY(String) no ambiguity is added and a clear API is kept.

Output was tested and is working as expected.

Mentions as this only targets Dart code (like required in the PR checklist): @jaumard @josh-burton @amondnet @sbu-WBT @kuhnroyal @agilob @ahmednfwela

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Summary by cubic

Added removal methods for auth credentials in dart-dio API clients so apps can revoke tokens/keys at runtime without recreating the client.

• New Features
  • removeOAuthToken(name) removes tokens from OAuthInterceptor.
  • removeBearerAuth(name) removes tokens from BearerAuthInterceptor.
  • removeBasicAuth(name) removes credentials from BasicAuthInterceptor.
  • removeApiKey(name) removes keys from ApiKeyAuthInterceptor.

^{Written for commit 76736b2. Summary will update on new commits.}

[cubic-dev-ai]

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