Add Cloud Code custom error playground example

[cbaker6]

• Add playground example of throwing cloud code custom error
• Prepare for release

[codecov]

Codecov Report

Merging #167 (775bed5) into main (457ef7c) will increase coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #167      +/-   ##
==========================================
+ Coverage   82.17%   82.20%   +0.03%     
==========================================
  Files          70       70              
  Lines        6596     6596              
==========================================
+ Hits         5420     5422       +2     
+ Misses       1176     1174       -2     

Impacted Files	Coverage Δ
Sources/ParseSwift/Types/Query.swift	93.38% <0.00%> (+0.17%)	⬆️
Sources/ParseSwift/Coding/AnyEncodable.swift	61.84% <0.00%> (+0.65%)	⬆️

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