Everywhere: Use to_number<T> instead of to_{int,uint,float,double}

In a bunch of cases, this actually ends up simplifying the code as
to_number will handle something such as:

```
Optional<I> opt;
if constexpr (IsSigned<I>)
    opt = view.to_int<I>();
else
    opt = view.to_uint<I>();
```

For us.

The main goal here however is to have a single generic number conversion
API between all of the String classes.

Userland/Services/FileOperation/main.cpp

@@ -358,7 +358,7 @@ ByteString deduplicate_destination_file_name(ByteString const& destination)
     auto last_hyphen_index = title_without_counter.find_last('-');
     if (last_hyphen_index.has_value()) {
         auto counter_string = title_without_counter.substring_view(*last_hyphen_index + 1);
-        auto last_counter = counter_string.to_uint();
+        auto last_counter = counter_string.to_number<unsigned>();
         if (last_counter.has_value()) {
             next_counter = *last_counter + 1;
             title_without_counter = title_without_counter.substring_view(0, *last_hyphen_index);

Userland/Services/LaunchServer/Launcher.cpp

@@ -397,7 +397,7 @@ bool Launcher::open_file_url(const URL& url)
         url.query()->bytes_as_string_view().for_each_split_view('&', SplitBehavior::Nothing, [&](auto parameter) {
             auto pair = parameter.split_view('=');
             if (pair.size() == 2 && pair[0] == "line_number") {
-                auto line = pair[1].to_int();
+                auto line = pair[1].template to_number<int>();
                 if (line.has_value())
                     // TextEditor uses file:line:col to open a file at a specific line number
                     filepath = ByteString::formatted("{}:{}", filepath, line.value());

Userland/Services/Taskbar/QuickLaunchWidget.cpp

@@ -339,7 +339,7 @@ void QuickLaunchWidget::load_entries(bool save)
         auto value = Config::read_string(CONFIG_DOMAIN, CONFIG_GROUP_ENTRIES, name);
         auto values = value.split(':');
 
-        config_entries.append({ values[0].to_int().release_value(), values[1] });
+        config_entries.append({ values[0].to_number<int>().release_value(), values[1] });
     }
 
     quick_sort(config_entries, [](ConfigEntry const& a, ConfigEntry const& b) {

Userland/Services/WebContent/WebDriverConnection.cpp

@@ -150,7 +150,7 @@ static ErrorOr<Web::DOM::Element*, Web::WebDriver::Error> get_known_connected_el
 {
     // NOTE: The whole concept of "connected elements" is not implemented yet. See get_or_create_a_web_element_reference().
     //       For now the element is only represented by its ID.
-    auto element = element_id.to_int();
+    auto element = element_id.to_number<int>();
     if (!element.has_value())
         return Web::WebDriver::Error::from_code(Web::WebDriver::ErrorCode::InvalidArgument, "Element ID is not an integer");
 
@@ -197,7 +197,7 @@ static ErrorOr<Web::DOM::ShadowRoot*, Web::WebDriver::Error> get_known_shadow_ro
 {
     // NOTE: The whole concept of "known shadow roots" is not implemented yet. See get_or_create_a_shadow_root_reference().
     //       For now the shadow root is only represented by its ID.
-    auto shadow_root = shadow_id.to_int();
+    auto shadow_root = shadow_id.to_number<int>();
     if (!shadow_root.has_value())
         return Web::WebDriver::Error::from_code(Web::WebDriver::ErrorCode::InvalidArgument, "Shadow ID is not an integer");
 

Userland/Services/WebDriver/Client.cpp

@@ -39,7 +39,7 @@ Client::~Client() = default;
 
 ErrorOr<NonnullRefPtr<Session>, Web::WebDriver::Error> Client::find_session_with_id(StringView session_id)
 {
-    auto session_id_or_error = session_id.to_uint<>();
+    auto session_id_or_error = session_id.to_number<unsigned>();
     if (!session_id_or_error.has_value())
         return Web::WebDriver::Error::from_code(Web::WebDriver::ErrorCode::InvalidSessionId, "Invalid session id");