Allow creating non-capturing regexps
Add comparison operators to what’s understood by ⌃T
When in Favorites folder, change Add → Remove From Favorites

In practice it is possible to be in a parent of the Favorites folder and expand items so that the symbolic links in favorites can be selected, this commit does not handle that case, as we would then also need to handle the case where items both inside and outside the Favorites folder were selected (at the same time).

Users who do these things are probably aware of how symbolic links work, and can use “Move to Trash”.

Closes #1089