Everywhere: Replace single-char StringView op. arguments with chars

This prevents us from needing a sv suffix, and potentially reduces the
need to run generic code for a single character (as contains,
starts_with, ends_with etc. for a char will be just a length and
equality check).

No functional changes.

Userland/Libraries/LibWeb/CSS/Parser/Block.cpp

@@ -22,7 +22,7 @@ String Block::to_string() const
     StringBuilder builder;
 
     builder.append(m_token.bracket_string());
-    builder.join(" ", m_values);
+    builder.join(' ', m_values);
     builder.append(m_token.bracket_mirror_string());
 
     return builder.to_string();

Userland/Libraries/LibWeb/CSS/Parser/Function.cpp

@@ -23,9 +23,9 @@ String Function::to_string() const
     StringBuilder builder;
 
     serialize_an_identifier(builder, m_name);
-    builder.append("(");
-    builder.join(" ", m_values);
-    builder.append(")");
+    builder.append('(');
+    builder.join(' ', m_values);
+    builder.append(')');
 
     return builder.to_string();
 }

Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp

@@ -2513,7 +2513,7 @@ Optional<StyleProperty> Parser::convert_to_style_property(Declaration const& dec
             property_id = PropertyID::Custom;
         } else if (has_ignored_vendor_prefix(property_name)) {
             return {};
-        } else if (!property_name.starts_with("-")) {
+        } else if (!property_name.starts_with('-')) {
             dbgln_if(CSS_PARSER_DEBUG, "Unrecognized CSS property '{}'", property_name);
             return {};
         }

Userland/Libraries/LibWeb/CSS/Parser/Rule.cpp

@@ -25,11 +25,11 @@ String Rule::to_string() const
     StringBuilder builder;
 
     if (is_at_rule()) {
-        builder.append("@");
+        builder.append('@');
         serialize_an_identifier(builder, m_at_rule_name);
     }
 
-    builder.join(" ", m_prelude);
+    builder.join(' ', m_prelude);
 
     if (m_block)
         builder.append(m_block->to_string());

Userland/Libraries/LibWeb/CSS/Selector.h

@@ -58,7 +58,7 @@ public:
                 // 3.
                 // - A is 1: Append "n" to result.
                 if (step_size == 1)
-                    result.append("n");
+                    result.append('n');
                 // - A is -1: Append "-n" to result.
                 else if (step_size == -1)
                     result.append("-n"sv);

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

@@ -72,7 +72,7 @@ Optional<StringView> extract_character_encoding_from_meta_element(String const&
         return {};
 
     if (lexer.consume_specific('"')) {
-        auto matching_double_quote = lexer.remaining().find("\"");
+        auto matching_double_quote = lexer.remaining().find('"');
         if (!matching_double_quote.has_value())
             return {};
 
@@ -81,7 +81,7 @@ Optional<StringView> extract_character_encoding_from_meta_element(String const&
     }
 
     if (lexer.consume_specific('\'')) {
-        auto matching_single_quote = lexer.remaining().find("'");
+        auto matching_single_quote = lexer.remaining().find('\'');
         if (!matching_single_quote.has_value())
             return {};
 

Userland/Libraries/LibWeb/HTML/WorkerDebugConsoleClient.cpp

@@ -53,7 +53,7 @@ JS::ThrowCompletionOr<JS::Value> WorkerDebugConsoleClient::printer(JS::Console::
         return JS::js_undefined();
     }
 
-    auto output = String::join(" ", arguments.get<JS::MarkedVector<JS::Value>>());
+    auto output = String::join(' ', arguments.get<JS::MarkedVector<JS::Value>>());
     m_console.output_debug_message(log_level, output);
 
     switch (log_level) {

Userland/Libraries/LibWeb/Origin.h

@@ -85,7 +85,7 @@ public:
 
         // 5. If origin's port is non-null, append a U+003A COLON character (:), and origin's port, serialized, to result.
         if (port() != 0) {
-            result.append(":");
+            result.append(':');
             result.append(String::number(port()));
         }
         // 6. Return result