Search functionality for workspace projects

[wonder-sk]

For workspaces with many projects it would be useful to have search functionality to quickly find projects. Right now one needs to use "double click for more" item in browser possibly multiple times, which slows things down.

There is already search for public projects, so it should be possible to extend it to private workspace projects as well.

[erpas]

QGIS Browser allows for filtering but that would only work if we have all the projects listed in the tree. I would vote for "fetch all projects" option instead of "double-click for more" or remove pagination altogether.

[erpas]

Also see https://github.com/MerginMaps/qgis-mergin-plugin/issues/384