ENH: Add Escape button handler to ctkConsole
ENH: Add Escape button handler to ctkConsole

Escape button does one of the followings:
- if there is a selection: clears the selection
- if the cursor is outside the input line: move the cursor to the input line
- clear the current command and rewind the command history

commontk/CTK,commontk/CTK,commontk/CTK,commontk/CTK