[PER-10632] Add EDTF datepicker, timepicker, and timezone-dropdown components

[aasandei-vsp]

The datepicker-input and timepicker-input have already been reviewed, but another fast glance would be nice.
The EDTF service is the one that's worth checking a bit more, I'd say.
The timezone-dropdown is going to be updated in a different story, but it is worth keeping the scaffolding for it, especially because I replaced the hardcoded timezones with IANA values.

These changes do not reflect in the UI at all, so no need for QA. Maybe just to check the app is loading.

Issue: PER-10632

[codecov]

Codecov Report

❌ Patch coverage is 76.33588% with 62 lines in your changes missing coverage. Please review.
✅ Project coverage is 50.29%. Comparing base (aaef917) to head (6fc773a).

Files with missing lines	Patch %	Lines
...nts/timepicker-input/timepicker-input.component.ts	62.06%	18 Missing and 4 partials ⚠️
...nts/datepicker-input/datepicker-input.component.ts	73.84%	14 Missing and 3 partials ⚠️
...c/app/shared/services/edtf-service/edtf.service.ts	83.96%	12 Missing and 5 partials ⚠️
...s/timezone-dropdown/timezone-dropdown.component.ts	81.81%	4 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1029      +/-   ##
==========================================
+ Coverage   49.97%   50.29%   +0.32%     
==========================================
  Files         348      351       +3     
  Lines       11502    11687     +185     
  Branches     1975     2043      +68     
==========================================
+ Hits         5748     5878     +130     
- Misses       5569     5610      +41     
- Partials      185      199      +14     

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