root_template(_prefix) cfgs now in TC section + Templates helper trait

The root_template_prefix/root_template config options can now be
supplied within the Template Controller config section (but still
supported in the main RapidApp section) because this makes better
logical sense from a user standpoint, and the helpers have been updated
to generate the examples of these in the new section. Have also now
separated out the sample Template Controller config into its own helper
trait "Templates" and is no longer within the base (only the main
RapidApp cfg key now is). The rapidapp.pl example usage has been updated
to show this helper