fix(color): Refreshing of GPS and DATE_TIME telemetry when using Value Widget

[frankiearzu]

Fixes #4170

Summary of changes:
With data-types who are not plain 32bit numbers, like GPS, Text, DATE_TIME, we have to populate the telemetry "value" with something that changes so that the "value" widget detects the change. The trick is to populate the "value" with a hash of the GPS or DATE_TIME complex value. The actual value for GPS and DateTime are stored in different variables.

The "value" widget was not displaying correctly DATE_TIME, fixed it (don't know why was moving the x coordinate -42 pixels!).
Change dateTime format to ISO 8601 date for color radios (YYYY-MM-DD HH:MM:SS).

NOTE: B&W was already this format (with 4 digits for year), and sensor log writing too... good for consistency.

NOT COMPILED FOR PRODUCTION: Updated Spektrun GPS testing code to change the values for GPS coordinates and Date without having the physical sensor (used previously captured data).

NOTE: Same PR worked for 2.9.1 as well as Main.

[frankiearzu]

GPS DATETIME not displaying correctly:

GPS Date displaying correctly: (FYI: my testing GPS time don't match the radio time).. Posible improvement: Show the month in text instead of number to avoid confusing in different country formats... challenge: localization

[frankiearzu]

Change dateTime format to ISO 8601 date for color radios (YYYY-MM-DD HH:MM:SS).

NOTE: B&W was already this format (with 4 digits for year), and sensor log writing too... good for consistency.

All dates consistent in screens and logs.

[pfeerick]

Fantastic! :) Yes, YYYY-MM-DD makes more sense to me, as you can straight away work out the year, and hopefully then figure out it's MM-DD after that.