[MOV] point_of_sale: reorganize static/src folder for easier navigation

Previously, the pos followed the convention established in Odoo for a
very long time to organize its static source files, one folder for js,
one for css and one for xml. In a component-based workflow this makes it
hard to work with as the template of a component is very far in the file
tree from the component itself.

This commit adopts the new convention from the web module, and locates
the js and xml of components in the same folder. It also renames all
files to follow the convention of the rest of odoo that file names
should be snake_case. Some files had additionally been renamed to more
accurately reflect their purpose.

The imports and some renaming will be done in a following commit to
allow git to track changes to the files better.

Part-of: odoo/odoo#123498

addons/point_of_sale/__manifest__.py

@@ -120,7 +120,8 @@
             # PoS files
             'point_of_sale/static/src/**/*',
             ('remove', 'point_of_sale/static/src/backend/**/*'),
-            ('remove', 'point_of_sale/static/src/entry/**/*'), # entry is only included in the prod bundle
+            # main.js boots the pos app, it is only included in the prod bundle as tests mount the app themselves
+            ('remove', 'point_of_sale/static/src/app/main.js'),
             # tour system FIXME: can this be added only in test mode? Are there any onboarding tours in PoS?
             'web/static/lib/jquery/jquery.js',
             'web_tour/static/src/tour_pointer/**/*',
@@ -137,7 +138,7 @@
         # Bundle that starts the pos, loaded on /pos/ui
         'point_of_sale.assets_prod': [
             ('include', 'point_of_sale._assets_pos'),
-            'point_of_sale/static/src/entry/main.js',
+            'point_of_sale/static/src/app/main.js',
         ],
         # Bundle for the unit tests at /pos/ui/tests
         'point_of_sale.assets_qunit_tests': [