Add drawBitmap method to ColorGraphicsDisplay interface

[mcbridejc]

Hey want to solicit thoughts on this change, or something like it, @TomSaw, @salkinium.

The ILI9341 driver offers a drawBitmap method, which can take a an Rgb565 bitmap as input, but this is not in the ColorGraphicsDisplay interface, and that's a problem because the ILI9341 has many template arguments so it's awkward to pass a reference to it.

Should we just add this virtual method to ColorGraphicsDisplay?

[salkinium]

I guess? I don't really have an overview anymore over the graphics API, so I'm delegating this to our expert @TomSaw…

[TomSaw]

Hey @mcbridejc. I'm sitting on a complete rewrite of the graphic APIs since 2021.
The new architecture is quite flexible and should solve your issue:
It allows copying+converting a bitmap in any imaginable colorspace (f.e. RGB565) stored somewhere (f.e. in flash memory) to any other writable memory in any imaginable colorspace, be it the local RAM or the displays CGRAM.

See these these dependent PRs:

• [color] Very generic colors: Rgb, Hsv and Gray #781
• [c++20] Rewrite Vector, Location2D, Matrix and LUDecomposition #782
• [hal] Support 16bit transfers for Spi #690
• Very generic graphic buffers [expected Q2 2022]
• Rewrite ILI9341 for new graphic APIs [expected Q2 2022]
• Adapt SSD1306 to new graphic APIs [expected Q2 2022]