LibURL/Pattern: Add a representation of a URL Pattern 'component'

A URL pattern consists of components such as the 'port', 'password'
'hostname', etc. A component is compiled from the input to the
URLPattern constructor and is what is used for matching against
URLs to produce a match result.

This is also where the regex dependency is introduced into LibURL
to support the URLPattern implementation.

Libraries/LibURL/CMakeLists.txt

@@ -10,5 +10,5 @@ set(SOURCES
 )
 
 serenity_lib(LibURL url)
-target_link_libraries(LibURL PRIVATE LibUnicode LibTextCodec)
+target_link_libraries(LibURL PRIVATE LibUnicode LibTextCodec LibRegex)
 target_compile_definitions(LibURL PRIVATE ENABLE_PUBLIC_SUFFIX=$<BOOL:${ENABLE_PUBLIC_SUFFIX_DOWNLOAD}>)

Libraries/LibURL/Pattern/Component.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2025, Shannon Booth <shannon@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/OwnPtr.h>
+#include <AK/String.h>
+#include <LibRegex/Regex.h>
+
+namespace URL::Pattern {
+
+// https://urlpattern.spec.whatwg.org/#component
+struct Component {
+    // https://urlpattern.spec.whatwg.org/#component-pattern-string
+    // pattern string, a well formed pattern string
+    String pattern_string;
+
+    // https://urlpattern.spec.whatwg.org/#component-regular-expression
+    // regular expression, a RegExp
+    OwnPtr<Regex<ECMA262>> regular_expression;
+
+    // https://urlpattern.spec.whatwg.org/#component-group-name-list
+    // group name list, a list of strings
+    Vector<String> group_name_list;
+
+    // https://urlpattern.spec.whatwg.org/#component-has-regexp-groups
+    // has regexp groups, a boolean
+    bool has_regexp_groups {};
+};
+
+}