feat: retry URL connection on error

[cbaker6]

New Pull Request Checklist

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

Issue Description

If a URL response error is received, the SDK currently returns the error to the developer without retrying. This causes the developer to handle retries themselves.

Fixed additional bugs:

• Fixed an issue where an annonymous couldn't be turned into a regular user using signup
• The default ACL is now deleted from the keychain when a user is logged out. This previously caused an issue when logging out a user and logging in as a different user caused all objects to only have ACL permisions for the logged in user

Related issue: #n/a

Approach

Add a retry mechanism to the SDK that randomly (up to 3 seconds each) tries to reconnect up to 5 times. The developer can increase or reduce the amount of retries when configuring the SDK.

TODOs before merging

• Add tests
• Improve and simplify sync/async URL execution
• Fix bugs
• Updated Playgrounds
• 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 #291 (d704ad4) into main (ae47862) will decrease coverage by 0.08%.
The diff coverage is 83.73%.

@@            Coverage Diff             @@
##             main     #291      +/-   ##
==========================================
- Coverage   82.46%   82.38%   -0.09%     
==========================================
  Files         104      104              
  Lines       10607    10659      +52     
==========================================
+ Hits         8747     8781      +34     
- Misses       1860     1878      +18     

Impacted Files	Coverage Δ
Sources/ParseSwift/Objects/ParseInstallation.swift	77.71% <59.25%> (+0.08%)	⬆️
Sources/ParseSwift/Extensions/URLSession.swift	72.46% <68.75%> (-0.64%)	⬇️
Sources/ParseSwift/API/API+Command.swift	82.47% <70.12%> (-1.71%)	⬇️
...urces/ParseSwift/API/API+NonParseBodyCommand.swift	75.48% <76.92%> (+0.31%)	⬆️
Sources/ParseSwift/Types/ParseFile.swift	79.80% <87.50%> (-0.33%)	⬇️
Sources/ParseSwift/Objects/ParseUser.swift	80.31% <91.46%> (+0.27%)	⬆️
Sources/ParseSwift/Objects/ParseObject.swift	76.11% <93.33%> (+0.10%)	⬆️
...Authentication/Protocols/ParseAuthentication.swift	71.27% <100.00%> (+0.29%)	⬆️
Sources/ParseSwift/Coding/ParseEncoder.swift	73.88% <100.00%> (+0.06%)	⬆️
Sources/ParseSwift/LiveQuery/ParseLiveQuery.swift	72.92% <100.00%> (-0.16%)	⬇️
... and 10 more

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