This adds a QRcode of the "url_root/wallet?usr=#####&wal=####" so that
the user can create a wallet on desktop and easily use it on his phone.
Also, in a use case where the <User Manager> extension is used, the
manager can create a wallet and show the QRcode for the user to take it
(e.g. in a hotel front desk the clerk creates it and the user takes it
in his phone browser, to pay for laundry, massage, soda machine...)
a big refactor that:
- fixes some issues that might have happened (or not) with asynchronous
reactions to payments;
- paves the way to https://github.com/lnbits/lnbits/issues/121;
- uses more async/await notation which just looks nice; and
- makes it simple(r?) for one extension to modify stuff from other extensions.
still fallback to the invoice polling (now with a 5 seconds interval
because less than that is too annoying).
this fixes issues with /lnurlwallet invoices not getting paid in time,
so we update the UI automatically when they do get paid.
(see https://t.me/lnbits/7069)
instead of multiple keys/macaroons with different permissions we request only one.
if someone wants to use lnbits with an invoice macaroon they're free to do it and
we will just fail on 'pay' methods, as before.
this also grandfathers the previous environment variables names so everything keeps
working without people having to change their setups.
in the meantime some bugs with lntxbot and c-lightning were fixed and the `requests`
dependency was eliminated because I can't organize myself into meaningful chunks of
changes.
- also center-align icons in main table.
- and use "x time ago" instead of raw dates by default in main table
(raw date is accessible on a tooltip, on the modal and on the CSV export).
