Fix TextEdit minimap tab drawing and click check

[kitbdev]

• Fixes TextEdit minimap adds an extra space for tab characters compared to spaces #87453
• Fixes Script editor minimap incorrectly renders the space taken by tabs #72876
• Fixes Minimap bottom area selects/drags code instead #63842

Fixes color leak from last color used in minimap to the lookup_symbol_word underline (hold control and hover).

Rewrites the character drawing logic to use a for loop instead of continues, so it can check the next character without needing to go back. This simplifies the logic and was needed to calculate the tab alignment since it can't be reversed.

Also clarified in the docs that the minimap text is fixed-width, since if the font used is not monospaced then it won't match.

Example text:

Before:

After:

[akien-mga]

Thanks!