fix: link with rel="alternate" should be unique based on hrefLang

[ignatiusreza]

since it's kinda hard to add support for this within the current code base.. I refactor the implementation for deciding which key is considered the primary key a bit.. the updated code should also fix #279..

within the updated code, priority for which keys should be considered first is based on the primaryAttributes array given to getTagsFromPropsList (leftmost first).. this makes the ordering the attributes appear in user code irrelevant..

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Merging #318 into master will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #318      +/-   ##
==========================================
+ Coverage   97.59%   97.62%   +0.03%     
==========================================
  Files           3        3              
  Lines         291      295       +4     
==========================================
+ Hits          284      288       +4     
  Misses          7        7

Impacted Files	Coverage Δ
src/HelmetConstants.js	100% <ø> (ø)	⬆️
src/HelmetUtils.js	96.91% <100%> (+0.05%)	⬆️

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[louisremi]

We'd be willing to send a small Amazon gift card in exchange for having this PR merged :-)

[vince1995]

Any progress on this?