nemo-view.c: Don't act on stale filterbar text

The key event handler has a 100ms callback for updating the filtered
view, to prevent excessive updates while typing. But if the user
performs a key-based action instead (like activate or navigation) it
could end up acting on a stale view.

Apply the filter immediately before propagating these types of key
events so it keeps up with the user's input.

properties-window: Fix permission checkboxes needing two clicks with …

…multiple files. (#3845)

initial_permission_state_consistent() stored the full mode of the
first file but compared the other files against it after masking,
so with more than one file the initial state never looked
consistent. Enabling a permission checkbox then went to the
'mixed' state and restored the original permissions, and only the
second click actually applied the change.

Fixes #3641

nemo-tree-sidebar.c: Fix context menu handling for invalid rows. (#3840)