Fix payment icon layout issue with Twenty Twenty theme (non-mobile layout)

[nerrad]

While testing 2.7.0, I noticed that with Twenty Twenty, the payment method icons for payment methods are incorrectly positioned:

They should be on the same line as the text content. Since they are at least left aligned, this isn't a huge issue but I think it would still be good to be consistent across themes for this.

[haszari]

Related: based on this comment from @LevinMedia, we are moving away from having a generic icons on payment methods; icons should be used for recognisable payment method brands only (example: PayPal).

With that in mind, we can simply remove the cheque icon and the generic CC icon (from Stripe Credit Card), which will also "fix" this theme problem. Should be a nice clean PR :)