Add custom browser support

[WilliamDenniss]

• An UICoordinator for iOS to support auth with a custom iOS browser like Chrome or Firefox.
• Implements Add support for other browsers on iOS #200.

[codecov-io]

Codecov Report

Merging #201 into master will decrease coverage by 1.51%.
The diff coverage is 8.08%.

@@            Coverage Diff             @@
##           master     #201      +/-   ##
==========================================
- Coverage   68.03%   66.51%   -1.52%     
==========================================
  Files          40       41       +1     
  Lines        3898     3993      +95     
  Branches       73       73              
==========================================
+ Hits         2652     2656       +4     
- Misses       1244     1335      +91     
  Partials        2        2

Impacted Files	Coverage Δ
...e/iOS/OIDAuthorizationUICoordinatorCustomBrowser.m	0% <0%> (ø)
Source/OIDURLQueryComponent.m	91.96% <100%> (+0.29%)	⬆️

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