Add Bash/Readline-style character search:
- Ctrl+] enters forward jump mode, awaits next character, jumps to it
- Ctrl+Alt+] does the same but searches backward
- Multi-line search
- Case-sensitive matching
- Pressing the hotkey again cancels; control chars cancel and fall
through
- Add alt+b/alt+f as alternative bindings for cursorWordLeft/cursorWordRight
- Add ctrl+d as alternative binding for deleteCharForward
- Fix ctrl+d in custom editor to perform delete when text is present
(previously it was always consumed, even with non-empty input)
Closes#1043
Co-authored-by: Jason Ish <ish@unx.ca>
