Berry animation improvements

[s-hadinger]

Description:

Berry animation improvements:

• simplified PaletteGradientAnimation
• rationalized range to 0..255 in OscillatorValueProvider
• new syntax highlighter of *.anim for VSCode

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.8
• The code change is tested and works with Tasmota core ESP32 V.3.1.6
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass