Refactor some other array extensions

[LucianoPAlmeida]

Continuation of #512
Still related to #427, hope to find time to take a more detailed look :))

Checklist

• I checked the Contributing Guidelines before creating this request.
• New extensions are written in Swift 4.
• New extensions support iOS 8.0+ / tvOS 9.0+ / macOS 10.10+ / watchOS 2.0+.
• I have added tests for new extensions, and they passed.
• All extensions have a clear comments explaining their functionality, all parameters and return type in English.
• All extensions are declared as public.
• I have added a changelog entry describing my changes.

[codecov]

Codecov Report

Merging #516 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #516      +/-   ##
==========================================
+ Coverage    93.8%   93.81%   +<.01%     
==========================================
  Files          65       66       +1     
  Lines        2762     2765       +3     
==========================================
+ Hits         2591     2594       +3     
  Misses        171      171

Flag	Coverage Δ
#ios	93.81% <100%> (ø)	⬆️
#osx	93.81% <100%> (ø)	⬆️
#tvos	93.81% <100%> (ø)	⬆️

Impacted Files	Coverage Δ
...urces/Extensions/SwiftStdlib/ArrayExtensions.swift	100% <ø> (ø)	⬆️
...SwiftStdlib/RandomAccessCollectionExtensions.swift	100% <100%> (ø)
...tStdlib/RangeReplaceableCollectionExtensions.swift	100% <100%> (ø)	⬆️

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[SwifterSwiftBot]

	4 Messages
📖	Thank you for submitting a pull request to SwifterSwift. The team will review your submission as soon as possible.
📖	Executed 487 tests, with 0 failures (0 unexpected) in 2.888 (3.306) seconds
📖	Executed 457 tests, with 0 failures (0 unexpected) in 1.980 (2.451) seconds
📖	Executed 331 tests, with 0 failures (0 unexpected) in 1.227 (1.577) seconds

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[omaralbeik]

LGTM, thanks @LucianoPAlmeida 👍

[LucianoPAlmeida]

Thank you guys 👍