- alternative to #3669

- transitions always enabled (use delay 0 to disable)
- optimisation in on/off fade
- fix for palette/color blend when blending style is not fade
- various tweaks and optimisations

- as requested by @willmmiles & @tkadauke

- small speed optimisations

- copies the source segment
- brightness of segment is relative to source segment
- optionally shifts the color hue
- invert, transpose, mirror work
- if source or targets do not match in size, smallest size is copied
- unused pixels fade to black (allows overlapping segments)
- if invalid source ID is set, segment just fades to black
- added a rgb2hsv conversion function as the fastled variant is inaccurate and buggy

note: 1D to 2D and vice versa is not supported

target segment now also copies the source settings (mirror, grouping, spacing, transpose) so the target looks exactly like the source. inverting can still be set independently.
note: the bug in line 214 of FX_2Dfcn.cpp missing `start` needs to be fixed for it to work properly in 2D.

- added color adjust function with support for hue, lightness and brightness
- colors can now be adjusted in hue, saturation and brightness
- added  `getRenderedPixelXY()` function (credit @willmmiles)
- source is now accurately copied, even 1D->2D is possible
- fix for segment offset not being zero in 2D in `getRenderedPixelXY()`
- added checkmark to copy source grouping/spacing (may remove again)
- tested many different scenarios, everything seems to work

- removed 'copy grouping/spacing' option
- added 'Switch axis' instead (in 2D -> 1D copy this chooses x or y axis to be copied)
- optimized for code size and speed by not using CRGB (where possible) and not returning struct in `rgb2hsv()`

added alias function to accept CRGB value.
this is more versatile for future uses.
also removed some whitespaces