mru: Sensitivity of select-on-hover in recents switcher

[topisani]

In the mru switcher, any small movement of the mouse will select the hovered window. This means, when using a sensitive mouse, i cannot use repeated alt-tab in the switcher without taking my hand off the mouse, and/or moving the cursor out of the preview area.

I think the simplest solution would be to disable select-on-hover in the switcher and have to click a window to select it with the cursor, but this should maybe be behind a config toggle if anyone prefers the current solution.

Alternatively, logic like in focus-follows-mouse could be used to require moving the mouse over the edge of a preview to select it, or simply a cutoff requiring the mouse to move at least X pixels to change selection.