Before this commit:
===================
Tax mapping used for Eat In/Take Out and the tax button behaved inconsistently
in the case of tax-inclusive prices.

Current behavior:
- Eat In/Take Out applies the fiscal position on the product screen but does not
  impact the order lines, maintaining the same sales price (tax-inclusive).
  Example: Sales price = 10 (with 12% tax included).

- The tax button behaves differently by applying the fiscal position on the
  product screen and the order lines, changing the unit price on the orderlines
  after fiscal position adjustment.
  Example: Sales price = 10 (with 6% tax included).

After this commit:
====================
If the Eat In/Take Out configuration is active:

Updated behavior:
- Replaced the `Tax` button with a `Takeaway` button, set `Dine In` as the
  default button, and on click, change the button to `Takeaway` and apply
  the takeaway fiscal position.

- `Takeaway` button will now maintain the original unit price on the order line
  after the fiscal position is applied. Example: Sales price = 10
  (with 12% tax included) changes to 10 (with 6% tax included) after
  fiscal position adjustment, but the order line will still show the original
  sales price of 10.

task - 3935347