[ADD] cloc: count loc in style file and from imported module

Context
-------

Web design specific require a lot of work and need maintenance.
So far the style files were not taken into account despite the
amount of maintenance they require.

With this commit they are going to be counted,
knowing they still can be excluded in the manifest.

Imported module allow to deploy frontend assets: stylesheet,
javascript, xml template and Qweb view that require
as well some maintenance. They are going to be counted

Implementation
--------------

- Add method to parse css and scss file
- Include .scss and .css file in the count

- Add external_id to attachment that store
  frontend asset of imported module
- Find all attachment with .js, .css, .scss, .xml
  from imported module
- Find qweb view from imported module
- cound the content of the attachment and the qweb view

closes odoo/odoo#85854

Signed-off-by: Christophe Simonis <chs@odoo.com>