Everywhere: Rename to_{string => deprecated_string}() where applicable

This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.

One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.

Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp

@@ -109,7 +109,7 @@ JS::GCPtr<DOM::Attr> prescan_get_attribute(DOM::Document& document, ByteBuffer c
         } else if (input[position] == '\t' || input[position] == '\n' || input[position] == '\f' || input[position] == '\r' || input[position] == ' ')
             goto spaces;
         else if (input[position] == '/' || input[position] == '>')
-            return *DOM::Attr::create(document, attribute_name.to_string(), "");
+            return *DOM::Attr::create(document, attribute_name.to_deprecated_string(), "");
         else
             attribute_name.append_as_lowercase(input[position]);
         ++position;
@@ -121,7 +121,7 @@ spaces:
     if (!prescan_skip_whitespace_and_slashes(input, position))
         return {};
     if (input[position] != '=')
-        return DOM::Attr::create(document, attribute_name.to_string(), "");
+        return DOM::Attr::create(document, attribute_name.to_deprecated_string(), "");
     ++position;
 
 value:
@@ -134,13 +134,13 @@ value:
         ++position;
         for (; !prescan_should_abort(input, position); ++position) {
             if (input[position] == quote_character)
-                return DOM::Attr::create(document, attribute_name.to_string(), attribute_value.to_string());
+                return DOM::Attr::create(document, attribute_name.to_deprecated_string(), attribute_value.to_deprecated_string());
             else
                 attribute_value.append_as_lowercase(input[position]);
         }
         return {};
     } else if (input[position] == '>')
-        return DOM::Attr::create(document, attribute_name.to_string(), "");
+        return DOM::Attr::create(document, attribute_name.to_deprecated_string(), "");
     else
         attribute_value.append_as_lowercase(input[position]);
 
@@ -150,7 +150,7 @@ value:
 
     for (; !prescan_should_abort(input, position); ++position) {
         if (input[position] == '\t' || input[position] == '\n' || input[position] == '\f' || input[position] == '\r' || input[position] == ' ' || input[position] == '>')
-            return DOM::Attr::create(document, attribute_name.to_string(), attribute_value.to_string());
+            return DOM::Attr::create(document, attribute_name.to_deprecated_string(), attribute_value.to_deprecated_string());
         else
             attribute_value.append_as_lowercase(input[position]);
     }

Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp

@@ -170,7 +170,7 @@ void HTMLParser::run()
             break;
         auto& token = optional_token.value();
 
-        dbgln_if(HTML_PARSER_DEBUG, "[{}] {}", insertion_mode_name(), token.to_string());
+        dbgln_if(HTML_PARSER_DEBUG, "[{}] {}", insertion_mode_name(), token.to_deprecated_string());
 
         // https://html.spec.whatwg.org/multipage/parsing.html#tree-construction-dispatcher
         // As each token is emitted from the tokenizer, the user agent must follow the appropriate steps from the following list, known as the tree construction dispatcher:
@@ -954,7 +954,7 @@ void HTMLParser::flush_character_insertions()
 {
     if (m_character_insertion_builder.is_empty())
         return;
-    m_character_insertion_node->set_data(m_character_insertion_builder.to_string());
+    m_character_insertion_node->set_data(m_character_insertion_builder.to_deprecated_string());
     m_character_insertion_node->parent()->children_changed();
     m_character_insertion_builder.clear();
 }
@@ -3604,7 +3604,7 @@ DeprecatedString HTMLParser::serialize_html_fragment(DOM::Node const& node)
             else
                 builder.append(ch);
         }
-        return builder.to_string();
+        return builder.to_deprecated_string();
     };
 
     // 2. Let s be a string, and initialize it to the empty string.
@@ -3752,7 +3752,7 @@ DeprecatedString HTMLParser::serialize_html_fragment(DOM::Node const& node)
     });
 
     // 5. Return s.
-    return builder.to_string();
+    return builder.to_deprecated_string();
 }
 
 // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#current-dimension-value

Userland/Libraries/LibWeb/HTML/Parser/HTMLToken.cpp

@@ -8,7 +8,7 @@
 
 namespace Web::HTML {
 
-DeprecatedString HTMLToken::to_string() const
+DeprecatedString HTMLToken::to_deprecated_string() const
 {
     StringBuilder builder;
 
@@ -70,7 +70,7 @@ DeprecatedString HTMLToken::to_string() const
         builder.appendff("@{}:{}-{}:{}", m_start_position.line, m_start_position.column, m_end_position.line, m_end_position.column);
     }
 
-    return builder.to_string();
+    return builder.to_deprecated_string();
 }
 
 }

Userland/Libraries/LibWeb/HTML/Parser/HTMLToken.h

@@ -315,7 +315,7 @@ public:
 
     Type type() const { return m_type; }
 
-    DeprecatedString to_string() const;
+    DeprecatedString to_deprecated_string() const;
 
     Position const& start_position() const { return m_start_position; }
     Position const& end_position() const { return m_end_position; }

Userland/Libraries/LibWeb/HTML/Parser/HTMLTokenizer.cpp

@@ -2887,7 +2887,7 @@ void HTMLTokenizer::restore_to(Utf8CodePointIterator const& new_iterator)
 
 DeprecatedString HTMLTokenizer::consume_current_builder()
 {
-    auto string = m_current_builder.to_string();
+    auto string = m_current_builder.to_deprecated_string();
     m_current_builder.clear();
     return string;
 }