FX improvements and cleanup (#4145)

Improvements & merges of FX

- Scrolling Text: Gradient Palette support added
- Waving Cell: Improved with higher temporal resolution (smoother at lower speeds) and added additional mode setting and optional blurring
- Julia: added blur option
- Squared Swirl: added fade option

- Added smearing option to:
    - DNA
    - DNA Spiral
    - Drift
    - Drift Rose
    - Crazy Bees
    - Ripple
    - Colored Bursts
    - Frizzles
    - Lissajous
    - Sindots
    - Spaceships

- Added palette support to:
    - Crazy Bees
    - Polar Lights
    - Drift Rose

- Changed default palette handling (no more special treatment for some FX)
- Merged puddles and puddlepeak
- Merged Gravcenter, Gravcentric, Gravfreq and Gravimeter (saves 1.2k of flash)
- Merged meteor and meteor smooth
- Renamed police_base into mode_two_dots as that was just an alias
- Added 'Traffic Light' palette (originally defined in Polar Lights FX)
-  Firenoise: removed local palette, use fire palette -> slight change in looks (+bugfix)
- Some code cleanup (removed unused / commented stuff)
- Moved dev info for AR to the top so ist easier to find as a reference, also added link to KB there