Changing symbols to strings for Calendar

[sffc]

See #310

[codecov]

Codecov Report

Merging #356 into main will increase coverage by 4.31%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##             main     #356      +/-   ##
==========================================
+ Coverage   79.69%   84.01%   +4.31%     
==========================================
  Files          17       17              
  Lines        3413     3415       +2     
  Branches      353      384      +31     
==========================================
+ Hits         2720     2869     +149     
+ Misses        677      517     -160     
- Partials       16       29      +13

Impacted Files	Coverage Δ
polyfill/lib/datetime.mjs	81.7% <100%> (+1.76%)	⬆️
polyfill/lib/timezone.mjs	87.2% <100%> (+4.28%)	⬆️
polyfill/lib/time.mjs	74.77% <100%> (+1.71%)	⬆️
polyfill/lib/absolute.mjs	88.38% <100%> (+15.95%)	⬆️
polyfill/lib/date.mjs	72.04% <100%> (+3.53%)	⬆️
polyfill/lib/yearmonth.mjs	77.18% <100%> (+37.84%)	⬆️
polyfill/lib/monthday.mjs	81.2% <100%> (+25.87%)	⬆️
polyfill/lib/ecmascript.mjs	93% <0%> (+0.21%)	⬆️
... and 7 more

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[ljharb]

Suggested change

	id] : string;
	id : string;

altho this should ideally be an accessor on the prototype, rather than an own property?

[ptomato]

👍 from me; up to you whether to change id to an accessor or not

[sffc]

The id field is super provisional right now, and may be removed once we reach a conclusion on #293.