Add OAuth support

[cbaker6]

Depends on server PR: parse-community/parse-server#7257

• Add sync, async, and publisher OAuth
• Add test cases
• Add documentation
• Add changelog

[codecov]

Codecov Report

Merging #91 (404c725) into main (f3f2244) will increase coverage by 0.22%.
The diff coverage is 92.90%.

❗ Current head 404c725 differs from pull request most recent head 47683b2. Consider uploading reports for the commit 47683b2 to get more accurate results

@@            Coverage Diff             @@
##             main      #91      +/-   ##
==========================================
+ Coverage   81.02%   81.25%   +0.22%     
==========================================
  Files          65       65              
  Lines        5477     5600     +123     
==========================================
+ Hits         4438     4550     +112     
- Misses       1039     1050      +11     

Impacted Files	Coverage Δ
Sources/ParseSwift/API/Responses.swift	88.57% <ø> (ø)
Sources/ParseSwift/Objects/ParseUser.swift	82.39% <91.72%> (+1.17%)	⬆️
Sources/ParseSwift/API/API.swift	96.33% <100.00%> (+0.37%)	⬆️
Sources/ParseSwift/Objects/ParseUser+combine.swift	93.84% <100.00%> (+0.86%)	⬆️

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