Implement LEAP key function

The Canon Cat had "LEAP", a function to quickly nagivate text.

It is explained in https://youtu.be/o_TlE_U_X3c?t=212.


(On today's keyboards, we could e.g., use the Meta key or another key combination instead of the dedicated LEAP keys.)

According to https://patents.google.com/patent/US4806916A/ the patent on LEAP keys by Jef Raskin has expired in 2006. Could we implement it system-wide, e.g., in a Qt plugin?

The patent describes the LEAP keys in a somewhat long-winded way, but in principle it is quite simple: You can move the cursor by pressing the LEAP key (combination) and then typing some characters of the text location you would like to jump, or "leap" to. Similar to searching with Alt-F, but limited to the text field you are currently in, and not selecting the "found" text. Result: You do not need the mouse nor cursor keys to jump, or "leap", around in a text entry widget.