fix: default cache policy for ParseFile uses SDK default

[cbaker6]

New Pull Request Checklist

• I am not disclosing a vulnerability.
• I am creating this PR in reference to an issue.

Issue Description

ParseFile should use the default cache policy set when initializing the SDK.

Remove NSObject comparison from ParseOperation set as it doesn't work well with non NSObjects.

Related issue: #n/a

Approach

Switched policy to previous default policy and cleaned up documentation.

TODOs before merging

• Add entry to changelog
• Improve ParseOperation set method
• Add more tests to ParseOperationTests
• Add more tests to ParsePointerTests`
• Add changes to documentation (guides, repository pages, in-code descriptions)

[parse-github-assistant]

Thanks for opening this pull request!

• 🎉 We are excited about your hands-on contribution!

[codecov]

Codecov Report

Merging #274 (5d41508) into main (fa1e07f) will decrease coverage by 0.01%.
The diff coverage is 88.23%.

@@            Coverage Diff             @@
##             main     #274      +/-   ##
==========================================
- Coverage   82.25%   82.23%   -0.02%     
==========================================
  Files         103      103              
  Lines       10575    10577       +2     
==========================================
  Hits         8698     8698              
- Misses       1877     1879       +2     

Impacted Files	Coverage Δ
...ParseSwift/Objects/ParseInstallation+combine.swift	100.00% <ø> (ø)
...urces/ParseSwift/Objects/ParseObject+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Objects/ParseUser+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParseConfig+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParseFile.swift	80.13% <ø> (-0.45%)	⬇️
Sources/ParseSwift/Operations/ParseOperation.swift	80.85% <80.00%> (-0.57%)	⬇️
Sources/ParseSwift/Types/Pointer.swift	81.42% <100.00%> (+1.74%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update fa1e07f...5d41508. Read the comment docs.