Add support for interleaved blitcopy

[tehKaiN]

Description

Makes the blitCopy() significantly faster when using on interleaved bitmaps. The showcase twister is faster now.

Also fixes modulo calculations for blitCopyAligned() when using mixed interleaved/non-interleaved bitmaps.

Checklist

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.

[tehKaiN]

What's worrying is that the twister has some odd garbage when switched to interleaved blits. On non-interleaved blits everything is fine. I see no way of reproducing that in isolated test case. 👀

[tehKaiN]

works stable enough