Add support for configuring template directories

[jmcgill298]

Still need to add documentation for this, but precedence would be:

• extra-vars: -e template_dir=$template_directory
• env: export TEMPLATE_DIR=$template_directory
• static: templates/

Also:

• made quotes consistent
• Use loop_var to name the looping variable
• Updated with_first_found to use lookup as per Ansible's current best practice

[FragmentedPacket]

+1 for this feature