[Enhancement] Investigate use of js-beautify to format the `*.tpl` files

[JohnVillalovos]

https://github.com/beautifier/js-beautify can be used to format Smarty template files *.tpl

smarty-php/smarty#1136 (comment)

Investigate using this to format the files and add it to the CI system.

An initial example command:

find tpl -type f -iname '*.tpl' -print0 \
  | xargs --null js-beautify --type html --templating smarty --indent-size 4 --replace --eol '\n' --end-with-newline