* feat(Themes): add support for GTK3 dynamic theming
Instead of overriding named colors of all GTK3 themes via the config
directory file, only override named colors for each variant of the
adw-gtk3 theme (light and dark), and let GTK3 apps change themes
depending on the value of org.gnome.desktop.interface color-scheme.
* fix(Themes): apply requested changes
- remove gtk3 override if it's a symlink
- remove call to gtk.sh with old arg 'assets-only'
- append key to dconf path to respect dconf write signature
* refactor(Themes): separate 'include'/'apply' logic for GTK3 dynamic theming
* revert(Themes): reset timer between color-scheme refresh
- rename DMS_ENABLE_GTK4_REFRESH to DMS_ENABLE_GTK_REFRESH
- revert a3fba8
* feat(Themes): add 'remove' mode to gtk.sh
Allow to remove all inclusions and overrides for GTK.
* fix(Themes): backup adw-gtk3 original css in 'apply' (not 'include')
* style(Themes): rename argument 'include' to 'patch' for clarity
* ci: change to prek for pre-commit
* refactor: fix shellcheck warnings for the scripts
* chore: unify whitespace formatting
* nix: add prek to dev shell
bbedward