refactor: change masterKey to primaryKey

[cbaker6]

New Pull Request Checklist

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

Issue Description

The parse-platform doesn't use inclusive language. Though a change has been requested for 2+ years a number of times:

• Rename master branch, rename masterKey to primaryKey parse-community/parse-server#7584
• Rename master branch, rename masterKey to primaryKey parse-community/parse-server#7584 (comment)
• Rename master branch, rename masterKey to primaryKey parse-community/parse-server#7584 (comment)
• Restrict access scope of master key parse-community/parse-server#8218)
• https://community.parseplatform.org/t/terminology-and-depictions-across-parse-platform/2009

changes have still not been made.

Approach

Change masterKey to primaryKey to reflect inclusive language discussed in https://github.com/dialpad/inclusive-language#motivation

TODOs before merging

• Verify tests still build
• Add entry to changelog
• Add changes to documentation (guides, repository pages, in-code descriptions)

[codecov-commenter]

Codecov Report

Merging #2 (95a9560) into main (b9de57c) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main       #2      +/-   ##
==========================================
+ Coverage   90.34%   90.39%   +0.04%     
==========================================
  Files         161      161              
  Lines       16267    16319      +52     
==========================================
+ Hits        14697    14752      +55     
+ Misses       1570     1567       -3     

Impacted Files	Coverage Δ
...urces/ParseSwift/Objects/ParsePushStatusable.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParseFile+async.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParseFile+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParsePush+async.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParsePush+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParsePushStatus.swift	95.45% <ø> (ø)
Sources/ParseSwift/Types/ParseSchema+async.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/ParseSchema+combine.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/Query+async.swift	100.00% <ø> (ø)
Sources/ParseSwift/Types/Query+combine.swift	100.00% <ø> (ø)
... and 19 more

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