Generic CSV views

[DivineDominion]

CSV previously sported multiple variants and ways to access data that were supposed to be mutually exclusive. With this change, it now really is, ensured by the compiler.

[codecov-io]

Codecov Report

Merging #76 into master will decrease coverage by 0.83%.
The diff coverage is 86.66%.

@@            Coverage Diff             @@
##           master      #76      +/-   ##
==========================================
- Coverage   92.57%   91.74%   -0.84%     
==========================================
  Files          14       13       -1     
  Lines         431      424       -7     
==========================================
- Hits          399      389      -10     
- Misses         32       35       +3

Impacted Files	Coverage Δ
SwiftCSVTests/QuotedTests.swift	100% <100%> (ø)	⬆️
SwiftCSVTests/PerformanceTest.swift	100% <100%> (ø)	⬆️
SwiftCSVTests/EnumeratedViewTests.swift	88.57% <100%> (ø)	⬆️
SwiftCSVTests/TSVTests.swift	100% <100%> (ø)	⬆️
SwiftCSV/NamedView.swift	100% <100%> (ø)	⬆️
SwiftCSVTests/CSVTests.swift	100% <100%> (ø)	⬆️
SwiftCSVTests/URLTests.swift	100% <100%> (ø)	⬆️
SwiftCSV/EnumeratedView.swift	70.83% <22.22%> (-29.17%)	⬇️
SwiftCSV/CSV.swift	70.37% <91.66%> (-1.73%)	⬇️

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[DivineDominion]

Hmm I haven't had anyone else review this code yet; @lukestringer90 with your real-world application of SwiftCSV, what do you think about the separation of the numbered/named access to CSV from this branch?

[lukestringer90]

@DivineDominion I'll try and take a look for you when I'm next working on my project. Where is the best place to start looking to understand the changes you've made here?

[codecov-commenter]

Codecov Report

Merging #76 (a8af063) into master (1357bfc) will increase coverage by 1.17%.
The diff coverage is 97.82%.

❗ Current head a8af063 differs from pull request most recent head 2badb26. Consider uploading reports for the commit 2badb26 to get more accurate results

@@            Coverage Diff             @@
##           master      #76      +/-   ##
==========================================
+ Coverage   92.53%   93.70%   +1.17%     
==========================================
  Files          14       14              
  Lines         402      445      +43     
==========================================
+ Hits          372      417      +45     
+ Misses         30       28       -2     

Impacted Files	Coverage Δ
SwiftCSV/CSV.swift	66.66% <81.25%> (-4.77%)	⬇️
SwiftCSV/EnumeratedView.swift	100.00% <100.00%> (ø)
SwiftCSV/NamedView.swift	100.00% <100.00%> (ø)
SwiftCSV/String+Lines.swift	44.44% <100.00%> (+15.87%)	⬆️
SwiftCSVTests/CSVTests.swift	100.00% <100.00%> (ø)
SwiftCSVTests/EnumeratedViewTests.swift	90.47% <100.00%> (+4.76%)	⬆️
SwiftCSVTests/NewlineTests.swift	100.00% <100.00%> (ø)
SwiftCSVTests/PerformanceTest.swift	100.00% <100.00%> (ø)
SwiftCSVTests/QuotedTests.swift	100.00% <100.00%> (ø)
SwiftCSVTests/TSVTests.swift	100.00% <100.00%> (ø)
... and 1 more

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[DivineDominion]

@lukestringer90 I updated the PR to incorporate the v0.5.6 changes.

Offers ways to interact with a CSV via enumeration and also via key/value-like access. The tests should be indicative what's going on behind the scenes. It's mostly a refactoring of the old code that used to mix things up but then errored-out when you used the wrong combination of initial configuration and subsequent data access.

The main question I have is: does this improve the clarity of use and the overall features of the library? Is this a good, or e.g. an over-engineered way forward?