Checkout v2 finetuning (#4276)

* Indent all JSON files with two spaces

* Upgrade Vue.js

* Cheat mode improvements

* Show payment details in case of expired invoice

* Add logo size recommendation

* Show clipboard copy hint cursor

* Improve info area and wording

* Update BIP21 wording

* Invoice details adjustments

* Remove form; switch payment methods via AJAX

* UI updates

* Decrease paddings to gain space

* Tighten up padding between logo mark and the store title text

* Add drop-shadow to the containers

* Wording

* Cheating improvements

* Improve footer spacing

* Cheating improvements

* Display addresses

* More improvements

* Expire invoices

* Customize invoice expiry

* Footer improvements

* Remove theme switch

* Remove non-existing sourcemap references

* Move inline JS to checkout.js file

* Plugin compatibility

See Kukks/btcpayserver#8

* Test fix

* Upgrade vue-i18next

* Extract translations into a separate file

* Round QR code borders

* Remove "Pay with Bitcoin" title in BIP21 case

* Add copy hint to payment details

* Cheating: Reduce margins

* Adjust dt color

* Hide addresses for first iteration

* Improve View Details button

* Make info section collapsible

* Revert original en locale file

* Checkout v2 tests

* Result view link fixes

* Fix BIP21 + lazy payment methods case

* More result page link improvements

* minor visual improvements

* Update clipboard code

Remove fallback for old browsers. https://caniuse.com/?search=navigator.clipboard

* Transition copy symbol

* Update info text color

* Invert dark neutral colors

Simplifies the dark theme quite a bit.

* copy adjustments

* updates QR border-radius

* Add option to remove logo

* More checkout v2 test cases

* JS improvements

* Remove leftovers

* Update test

* Fix links

* Update tests

* Update plugins integration

* Remove obsolete url code

* Minor view update

* Update JS to not use arrow functions

* Remove FormId from Checkout Appearance settings

* Add English-only hint and feedback link

* Checkout Appearance: Make options clearer, remove Custom CSS for v2

* Clipboard copy full URL instead of just address/BOLT11

* Upgrade JS libs, add content checks

* Add test for BIP21 setting with zero amount invoice

Co-authored-by: dstrukt <gfxdsign@gmail.com>

BTCPayServer/Controllers/UIInvoiceController.UI.cs

@@ -928,14 +928,6 @@ namespace BTCPayServer.Controllers
             return Ok("{}");
         }
 
-        [HttpPost("i/{invoiceId}/Form")]
-        [HttpPost("invoice/Form")]
-        public IActionResult UpdateForm(string invoiceId)
-        {
-            // TODO: Forms integration 
-            return Ok();
-        }
-
         [HttpGet("/stores/{storeId}/invoices")]
         [HttpGet("invoices")]
         [Authorize(AuthenticationSchemes = AuthenticationSchemes.Cookie, Policy = Policies.CanViewInvoices)]