Add a filter on project chooser during thought processing

[degrown]

While processing a thought, if actionable the user can choose some additional data.
If this action has to be added in an existing project, a project chooser popup appears (see below)
This is a feature request about two enhancements:

• first, add a search field at the right of expand/collapse and order by buttons: in this way one can filter into the project names below, whether they're visible or collapsed (I've lots of projects, and selecting the right one is really a pain for me)
• plus: add some elasticity/intelligence to the window width; actually I think that the width is fixed, because doesn't matters the content, or the screen, or the parent window width.