E2E Test Suite

[kilrau]

Collection of some advanced test cases

• Test refund file download json & qr code, ideally with FF & Chrome on Desktop and Mobile each. Not a small feat since currently our tests use a stubbed dom, not an actual browser (compare Tests: Refund file download #399)
• Test if reading refund QR works (compare fix: increase refund QR size #606)
• Test address/invoice field with all sort of address types incl. unconfidential Liquid addresses (comprare fix: chain swaps to unconfidential Liquid addresses #605)