Properly fix the assignment of Control characters in keymap.tcl

https://github.com/FolkComputer/folk/commit/ab1541b59896448b2e57af272e0b097ec7f4e843 fixes this issue but feels like a hack. I have a hunch that the proper fix is to avoid adding `Control_*` characters to the list of chars or modifying `resolve` directly but I can't grok or debug it well tonight.

https://github.com/FolkComputer/folk/blob/b410c0678a56901fe62019110460334508bb3408/lib/keymap.tcl#L214-L224