Symbol fallback

[kspeyanski]

A couple of things here to consider:

• With version v44 of cldr-* packages, it seems the symbol field has been removed from the currensies.json files, unless it's a different symbol. This breaks scenarios where the symbol and the currency abbreviation are the same (e.g. CHF currency in de-CH lang/locale pair) — thus the added fallback from the first commit:
  
• The removal of the symbol field might not be intentional, but rather a regression, since I was not able to find any info on their changelog
• Adding a test case as the current one with the BGN currency actually have a dedicated symbol.
• The latests cldr version is 44.1, HOWEVER, they have a failed 44.1.0 deployment of cldr-core, which other packages have already listed as dependency. — thus the version bump
  

cc, @telerik/kendo-intl-reviewers

[tsvetomir]

Hm, that's weird. Let's hope the format doesn't flip-flop too much.

[kspeyanski]

@tsvetomir Reserving back to only tackling the bug in this PR, will follow up with a separate one to handle version bumps and tests