[IMP] point_of_sale: Add new settings form per POS

Purpose: Replace POS APP settings with a clean POS Form settings,
         one per POS

    - add state button for (active/inactive) archive/unarchive and remove boolean field.
    - remove 'Reprint Receipt' field from pos_reprint module and related code.
    - remove 'Multi-currencies' field and related code.
    - put 'Company' field under the 'Taxes' block and 'Sales Channel' under the 'Pricing' block.
    - add 'save' buttons to install needed modules manually.
    - removed constrains and set default fiscal value on fiscal position ids even if that not selected.
    - change the skip Receipt Screen label to a more appropriate one.
    - Tax help only appears when Tax-included is selected.

    * [IMP] point_of_sale: Removing multiple prices prod

    Purpose: The choice of the method for "Multiple price per product" was
    not appropriate for the Point Of Sale. Only the choice of the Pricelist
    make sense. So, only the Pricelist can be choosen in the POS config.

    * [IMP] point_of_sale, pos_discount, pos_restaurant:
            Generic module install

    Purpose: Before this improvement, some fields were used in pos.config to
             automatically install some modules.
             This fix tries to mimic the ResConfigSettings transient so that
             when a field starts with 'module_', it's automaticaly
             installed.