Support different bitmap types

[TinyCircuits]

Adding support for the following bitmap types (no support for compressed formats, only uncompressed):

• 1BPP 2 COLOR PALETTE/INDEX <- now supported!
• 4BPP 16 COLOR PALETTE/INDEX <- now supported!
• 8BPP 256 COLOR PALETTE/INDEX <- now supported!
• 16BPP RGB 565 <- always supported!
• 16BPP XRGB 1555 <- now supported!
• 16BPP ARGB 1555 <- now supported!
• 16BPP XRGB 4444 <- now supported!
• 16BPP ARGB 4444 <- now supported!
• ~24BPP RGB 888~
• ~32BPP XRGB 8888~
• ~32BPP ARGB 8888~

Note: X = unused portion

To do:

• [X] Parse all different bitmap types (as well as we can) and determine format (see above list)
• [X] For palette/indexed bitmap types (bpp < 16), place color table in RAM in RGB565 format (faster to copy colors to buffer this way). This allows for palettes to be changed at runtime by Python
• [X] Copy pixel/index table to RAM or FLASH and flip Y (data is stored upside down in bitmaps)
• [X] ~Convert 24 and 32-bit pixel data to 16-bit 565 with an alpha byte as well if the bitmap has it (easier to copy to screen buffer and makes drawing faster)~
• [X] Change internal engine API to fetch 16-bit 565 color from any texture type (using in-lining to avoid function calls per pixel, will still add an if or two)

[September 6th, 2024 update]: For now (or maybe forever) we're not going to support 24 or 32 bits bitmaps since they take up so much space and take a long time to copy to scratch (depending on size).

[ace-dent]

Useful resource is @jsummers Bitmap Test Suite: https://github.com/jsummers/bmpsuite