Implement more comprehensive notification system for user actions

[greatislander]

Is your feature request related to a problem? Please describe.

Currently notifications are presented using this controller:

coop-library/app/Controllers/App.php

Lines 16 to 28 in 65912a1

	public function notifications()
	{
	if (isset($_POST['do_not_track_viewed_resources'])) {
	return [
	[
	'title' => __('Settings saved'),
	'type' => 'success',
	'content' => sprintf('<p>%s</p>', __('Your settings have been saved.', 'coop-library'))
	]
	];
	}
	}

This only handles one situation (saving settings related to tracking resource views).

Describe the solution you'd like

A more flexible notification system could handle future actions like submitting resources, reporting issues or broken links, or suggesting edits.

Describe alternatives you've considered

Not applicable.

Additional context

Not applicable.