Feat Suggestion methods api

[G10xy]

Description

This PR implements the suggestions API so that users of this library can both fetch suggestions about users to follow and remove a suggested one.

This addresses #259

Type of Change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

Gradle check, gradle detect and gradle build

Mandatory Checklist

• My change follows the projects coding style
• 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
• New and existing unit tests pass locally with my changes

Other

Even both Rx counter parts and unit tests have been implemented

https://github.com/andregasser/bigbone/wiki/Mastodon-API-Coverage#methods needs to be updated after this has been merged!

[codecov]

Codecov Report

Merging #291 (7e8e600) into master (945ef7c) will increase coverage by 0.09%.
The diff coverage is 43.47%.

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #291      +/-   ##
============================================
+ Coverage     37.26%   37.35%   +0.09%     
- Complexity      387      393       +6     
============================================
  Files           107      110       +3     
  Lines          3118     3164      +46     
  Branches        186      187       +1     
============================================
+ Hits           1162     1182      +20     
- Misses         1834     1857      +23     
- Partials        122      125       +3     

Files	Coverage Δ
...e/src/main/kotlin/social/bigbone/MastodonClient.kt	33.09% <100.00%> (+0.23%)	⬆️
...lin/social/bigbone/api/method/SuggestionMethods.kt	75.00% <75.00%> (ø)
...ain/kotlin/social/bigbone/api/entity/Suggestion.kt	58.33% <58.33%> (ø)
...in/kotlin/social/bigbone/rx/RxSuggestionMethods.kt	0.00% <0.00%> (ø)

[PattaFeuFeu]

Thanks for your work here! 😊

I have some suggestions that we should implement before moving forward with this PR.

[PattaFeuFeu]

Thanks for your updates! Just two minor optional changes left for me, but other than that this’d be fine by me. 😊

[andregasser]

Approved. Thanks for the work! 👍