fix: improve threading support for .current objects

[cbaker6]

New Pull Request Checklist

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

Issue Description

Depending on how .current objects are used in an app, crashes can occur due to threading. Close #46

Approach

Add a synchronization queue to all .current objects.

TODOs before merging

• Add tests
• Add entry to changelog

[cbaker6]

@bcbeta can you see if the this branch addresses your problem in #37?

[codecov]

Codecov Report

Merging #45 (bd283ca) into main (9c70348) will decrease coverage by 0.00%.
The diff coverage is 98.55%.

@@            Coverage Diff             @@
##             main      #45      +/-   ##
==========================================
- Coverage   90.31%   90.30%   -0.01%     
==========================================
  Files         161      163       +2     
  Lines       16243    16322      +79     
==========================================
+ Hits        14670    14740      +70     
- Misses       1573     1582       +9     

Impacted Files	Coverage Δ
...es/ParseSwift/Protocols/ParseCloudable+async.swift	100.00% <ø> (ø)
.../ParseSwift/Protocols/ParseCloudable+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Protocols/ParseCloudable.swift	100.00% <ø> (ø)
Sources/ParseSwift/Storage/KeychainStore.swift	96.58% <ø> (ø)
...es/ParseSwift/Storage/ParsePrimitiveStorable.swift	94.73% <ø> (ø)
Sources/ParseSwift/Types/ParseHealth.swift	100.00% <ø> (ø)
Sources/ParseSwift/Storage/ParseStorage.swift	82.14% <75.00%> (ø)
Sources/ParseSwift/Utility.swift	97.56% <97.56%> (ø)
Sources/ParseSwift/API/API.swift	99.35% <100.00%> (ø)
Sources/ParseSwift/Extensions/URLSession.swift	86.37% <100.00%> (-1.36%)	⬇️
... and 16 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[bcbeta]

@bcbeta can you see if the this branch addresses your problem in #37?

I will get a release out next week and let you know how it goes. Thanks!

[cbaker6]

I will get a release out next week and let you know how it goes. Thanks!

When you try, you can link to tag https://github.com/netreconlab/Parse-Swift/releases/tag/5.0.0-beta.2

Note that there's a small breaking change when initializing the Swift SDK, you can choose add try to catch any errors or try? to ignore all errors. See below for an example:

Parse-Swift/ParseSwift.playground/Pages/1 - Your first Object.xcplaygroundpage/Contents.swift

Lines 18 to 22 in c7c83f1

	do {
	try initializeParse()
	} catch {
	assertionFailure("Error initializing Parse-Swift: \(error)")
	}