Everywhere: Split Error::from_string_literal and Error::from_string_view

Error::from_string_literal now takes direct char const*s, while
Error::from_string_view does what Error::from_string_literal used to do:
taking StringViews. This change will remove the need to insert `sv`
after error strings when returning string literal errors once
StringView(char const*) is removed.

No functional changes.

Userland/Libraries/LibCore/Command.cpp

@@ -22,7 +22,7 @@ ErrorOr<CommandResult> command(String const& command_string, Optional<LexicalPat
 {
     auto parts = command_string.split(' ');
     if (parts.is_empty())
-        return Error::from_string_literal("empty command"sv);
+        return Error::from_string_literal("empty command");
     auto program = parts[0];
     parts.remove(0);
     return command(program, parts, chdir);