Clean up endpoint definitions in methods classes

[PattaFeuFeu]

Description

In this PR, I cleaned up how we refer to endpoints:

1. Ensure that all endpoints start without a leading slash (api/v1/…, not /api/v1/…)
2. Ensure that all endpoints defined as a class-level val are named endpoint (or endpointV1 and endpointV2 if we have multiple) so that all method classes follow mostly the same structure
3. Ensure that all methods define their endpoints as class-level vals

Relates to #396

Type of Change

• Refactoring and cleanup

Breaking Changes

• None

How Has This Been Tested?

I ran existing unit tests through gradle check

Mandatory Checklist

• I ran gradle check and there were no errors reported
• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works
• All tests pass locally with my changes
• I have added KDoc documentation to all public methods

[codecov]

Codecov Report

Attention: 8 lines in your changes are missing coverage. Please review.

Comparison is base (198690f) 49.25% compared to head (a9773c1) 49.43%.

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #410      +/-   ##
============================================
+ Coverage     49.25%   49.43%   +0.18%     
  Complexity      714      714              
============================================
  Files           169      169              
  Lines          4769     4790      +21     
  Branches        312      312              
============================================
+ Hits           2349     2368      +19     
- Misses         2157     2159       +2     
  Partials        263      263              

Files	Coverage Δ
...kotlin/social/bigbone/api/method/AccountMethods.kt	87.50% <100.00%> (+0.08%)	⬆️
...n/social/bigbone/api/method/AnnouncementMethods.kt	90.47% <100.00%> (ø)
...ain/kotlin/social/bigbone/api/method/AppMethods.kt	75.00% <100.00%> (+1.31%)	⬆️
...n/kotlin/social/bigbone/api/method/BlockMethods.kt	100.00% <100.00%> (ø)
...otlin/social/bigbone/api/method/BookmarkMethods.kt	100.00% <100.00%> (ø)
...n/social/bigbone/api/method/ConversationMethods.kt	92.85% <100.00%> (+0.54%)	⬆️
...in/social/bigbone/api/method/CustomEmojiMethods.kt	100.00% <100.00%> (ø)
...tlin/social/bigbone/api/method/DirectoryMethods.kt	84.21% <100.00%> (+0.87%)	⬆️
...in/social/bigbone/api/method/DomainBlockMethods.kt	100.00% <100.00%> (ø)
...n/kotlin/social/bigbone/api/method/EmailMethods.kt	100.00% <100.00%> (ø)
... and 31 more

[andregasser]

Thanks for the cleanup 👍 . I had only one comment regarding test classes.

[andregasser]

All good.