[Plugins] Fuzzy find plugins and run them; unmount mountpoints from their subfolders...

[Plugins] Fuzzy find plugins and run them; unmount mountpoints from their subfolders (#977)

* Fuzzy find plugins and run them

* Hide find warning when $otherplugins is not set

* Fix prompt on error 2

* Use /home/mathieu

* unmount-parent plugin

* Add dependencies and shell description

* Add dependencies and fix CI issue?

* Improve fzfplug prompt, fix shellcheck warnings, restore mistakenly deleted line in README

* Typo

* Make both scripts POSIX-compliant and small improvements

* Final cosmetic changes

* bis

* Clarify description

* Typo

* Typo

* Better support for custom dirs and use bat if available

Co-authored-by: M <>