[FR]: Implement functionality from extension back-to-monitor@nathan818fr

[Fjodor42]

As per 6.4, cf. linuxmint/cinnamon-spices-extensions#814, the immensely useful Cinnamon extension Back to Monitor is no longer functional

The extension remembers window placement upon monitor disconnection, and restores windows to the old positions upon reconnection.

Unfortunately, cf. linuxmint/cinnamon-spices-extensions#814 (comment), the extension is no longer in active development, and there, the author suggests asking for official support for the functionality.

This discussion seeks to do exactly that.

Whether this gets implemented in the form of a fork of the extension, or whether it gets built in directly, is irrelevant to me, but the functionality itself is highly useful.