refactor(editor): the helpers repeated over the editor files are shared

The name of a node or "(no name)" was written out in twenty places and
four local functions, a lower-case copy of a text in four files, the
test for a number, the file name of a template made comparable and the
heading of a direction in three and two, the green main button of a
panel in five and the key=value parameters of a self-test command in
five. Each of them is one helper now: name_of, tall_button_height and
main_button with the panel helpers, numeric with format, normalized
with the include helpers, heading_of with the plan geometry and
selftest_values with the tools; lower gives way to ToLower.

editor/editorIncludeInfo.cpp

@@ -590,6 +590,12 @@ bool complete(include_info const &Info, int const Parameters, std::string *Issue
 	return issue.empty();
 }
 
+std::string normalized(std::string File)
+{
+	std::replace(File.begin(), File.end(), '\\', '/');
+	return ToLower(File);
+}
+
 std::string number(double const Value)
 {
 	std::ostringstream converter;