[FEAT] Add generation mode by color

[kesm]

Is your feature request related to a problem? Please describe.

When generating paintings, the drawing doesn’t become visible quickly enough, and the results aren’t always visually appealing.

Describe the solution you'd like

I’d like an option to generate paintings by colors, starting from the most frequent to the least frequent color (or the reverse). This way, the main shapes become visible faster.

Describe alternatives you've considered

The only alternatives are using the existing modes (rows, columns, circles, random), but none of them make the overall picture appear quickly or highlight the dominant colors first.

Additional context

No response

[skalsech]

it's a nice suggestion.

but first, a rework of pixel batching is needed. there is already a problem when your art is laying across different tiles, and you have to send only 1 or a few already accumulated pixels in old region to change to the new region instead of making 1 big proper batch. I think after that is refactored, we can proceed to make such a coords generation mode

[Patricklumowa]

we'll add this later