fix: don't use cache for fetching objects and files by default

[cbaker6]

New Pull Request Checklist

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

Issue Description

When objects or files are being “fetched”, they sometimes leverage the OS level cache and pull from cache if there was a cache hit. This can lead to unintended behavior as when a “fetch” is used, it implies fresh data from the server.

In addition, when caching a file that was downloaded via the SDK, the temporary file location is cached instead the new location the file was moved to. This results in a cache hit, but points to a file location that’s no longer valid.

Related issue: #226

Approach

For "fetching", the default cache policy is set for all ParseObject's and ParseFile's to not use cache. If the developer wants to use cache, they should pass the respective cache policy into options when calling the respective fetch method. The default cache policy for the SDK can be changed by the developer if needed:

Parse-Swift/Sources/ParseSwift/Parse.swift

Lines 33 to 37 in a64726f

	/// The default caching policy for all http requests that determines when to
	/// return a response from the cache. Defaults to `useProtocolCachePolicy`.
	/// See Apple's [documentation](https://developer.apple.com/documentation/foundation/url_loading_system/accessing_cached_data)
	/// for more info.
	var requestCachePolicy = URLRequest.CachePolicy.useProtocolCachePolicy

When fetching ParseFile, cache the final location the file was moved to instead of the temporary location

TODOs before merging

• Add tests
• Add entry to changelog
• 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 #272 (c0f8043) into main (a64726f) will decrease coverage by 0.09%.
The diff coverage is 87.01%.

@@            Coverage Diff             @@
##             main     #272      +/-   ##
==========================================
- Coverage   82.34%   82.25%   -0.10%     
==========================================
  Files         102      102              
  Lines       10525    10575      +50     
==========================================
+ Hits         8667     8698      +31     
- Misses       1858     1877      +19     

Impacted Files	Coverage Δ
...Authentication/Protocols/ParseAuthentication.swift	70.98% <ø> (ø)
Sources/ParseSwift/LiveQuery/Subscription.swift	68.35% <ø> (ø)
...es/ParseSwift/LiveQuery/SubscriptionCallback.swift	93.75% <ø> (ø)
...s/ParseSwift/Objects/ParseInstallation+async.swift	100.00% <ø> (ø)
...ParseSwift/Objects/ParseInstallation+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Objects/ParseObject+async.swift	100.00% <ø> (ø)
...urces/ParseSwift/Objects/ParseObject+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Objects/ParseUser+async.swift	100.00% <ø> (ø)
Sources/ParseSwift/Objects/ParseUser+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParseAnalytics.swift	98.13% <ø> (ø)
... and 21 more

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[cbaker6]

@vdkdamian can you try out this branch? Note that it will only fix your problem if was related to the caching I mentioned in #226 (comment) and #226 (comment). If this doesn't fix your issue, then you will have to look in other places in your code and SDK.

[vdkdamian]

@cbaker6 This solves my issue! I tested it multiple times on iOS, then multiple times on macOS. Everything is working fine for me now.