Add supplemental CLDR metaZones.json to TimeZonesProvider

[nordzilla]

CLDR metaZones.json contains

• information on which time zones belong to which metazones at given time periods.
• information on which time zone is preferred for a metazone in a given territory.

We need this information in order to determine the metazone ID from a zoned timestamp, and to make informed decisions in non-location fallback formats.

[sffc]

@nordzilla Can you split "information on which time zone is preferred for a metazone in a given territory." into its own issue so we can mark this issue as fixed?

[sffc]

@nordzilla Please act on the above.

[nordzilla]

Created issue #2684