This splits the bookmarks submodule into a seperate file, to make it easier to maintain (like how the search module was previously split out in #5697).
This also refactors bookmarks to require a new force option, to be more explicit about overriding existing bookmarks.
* nixos: remove with lib
* nix-darwin: remove with lib
* home-manager: remove with lib
* modules/accounts: remove with lib
* modules/config: remove with lib
* modules/i18n: remove with lib
* modules/misc: remove with lib
* modules: remove with lib
* modules/targets: remove with lib
* tests/modules/firefox: remove with lib
* tests/modules/services: remove with lib
