On Windows we ship compiled files

- Auto enable all plugins in the base folder, this allows package
maintainers to ship plugins

- Give plugins in the user folder priority over plugins in the base
folder

- Remove some unused dirs to reduce the size of the installation
- Add some needed executables

This is no problem because the signal is not emited if the platform
does not support it

Fixes #10152

The script has been moved to gajim-plugins repo.

- Don't clear the search entry when pressing the global search button
- Start a search automatically after pressing the button

Fixes #10134.

Logo without text is used, because it wasn't readable in the GUI anyway.
Part of #9049.