LibWeb+LibWebView+WebContent: Convert about:settings to a WebUI

Author: https://github.com/trflynn89
Commit: f05b0bfd5f
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4068

Services/WebContent/WebContentClient.ipc

@@ -108,10 +108,4 @@ endpoint WebContentClient
     did_find_in_page(u64 page_id, size_t current_match_index, Optional<size_t> total_match_count) =|
 
     request_worker_agent(u64 page_id) => (IPC::File socket) // FIXME: Add required attributes to select a SharedWorker Agent
-
-    request_current_settings(u64 page_id) =|
-    restore_default_settings(u64 page_id) =|
-    set_new_tab_page_url(u64 page_id, URL::URL new_tab_page_url) =|
-    request_available_search_engines(u64 page_id) =|
-    set_search_engine(u64 page_id, Optional<String> search_engine) =|
 }