Instance (un)block endpoint

And hide the block button for the local instance

src/main.rs

@@ -65,6 +65,7 @@ fn main() {
             routes::instance::admin,
             routes::instance::admin_instances,
             routes::instance::admin_instances_paginated,
+            routes::instance::toggle_block,
             routes::instance::update_settings,
             routes::instance::shared_inbox,
             routes::instance::nodeinfo,