Improve app-grid style and some other fixes
A bunch of improvements sparked by !1262 (merged) and !1563
* system-modal-dialog: Format signal definition
Use our current style before making changes
* system-modal-dialog: Don't process key event directly
Less code and helps the GTK4 migration. Also makes sure we don't
interfere with other event handling.
Can be reworked to use gtk_widget_class_add_binding_action then.
* top-panel: Format signal definition
Use our current style before making changes
* top-panel: Don't process key event directly
Less code and helps the GTK4 migration. As we don't have a "closed"
signal we'll use "activated" which is enough to make `PhoshShell` toggle
fold.
Can be reworked to use gtk_widget_class_add_binding_action then.
* top-panel: Move settings upwards
As we don't have a dedictated "close" signal "activate" will do.
This allows us to drop the `packaging` elements which eases the reading
flow and eases the GTK4 transition.
* app-grid-base-button: Make abstract
It can only serve as base class for other buttons
* app-grid-base-button: Remove css name
We style the derived classes.
* app-grid-button: Use alpha on activation and search too
Amends df0f30580 ("app-grid-button: Use alpha when focused")
* app-grid-folder-button: Let style match the app-grid-button
Amends df0f30580 ("app-grid-button: Use alpha when focused")
* app-grid: Add outline around selected search item
Makes it easier to identify when using a background
@arun-mani-j @gautham_x please have a look