Draft: Fix various single-click-to-open problems

Disable it when the app enabled mouse tracking. Otherwise, the click will be handled by the terminal and the app, and conflicts.

So if the app handles mouse, single-click will not open URL/file, even if the "single click to open" is on. Ctrl-click still works.

This should prevent the "single click to open" option to interfere with VIM and other TUI apps, but still works in the shell prompt and TUI apps without mouse handling.

@ngraham and @vladz would you mind testing if this fixes your previous problems with "single click to open"?

@fanzhuyifan maybe we can reconsider enabling "single click to open" by default with this?

EDIT: According to @vladz (and I can confirm), single-click-to-open also has problems in shell prompt, when mouse is not tracked, a double-click would also register as single-click, making double-click-to-select-word dysfunctional. This need to be fixed, too.

EDIT2: I changed single-click-to-open to only work on the left button, so it doesn't conflict with middle-click-to-paste. Unsure if that's correct.