Support NUT-XX (signatures on quotes) for mint and wallet side (#670)

* nut-19 sign mint quote

* ephemeral key for quote

* `mint` adjustments + crypto/nut19.py

* wip: mint side working

* fix import

* post-merge fixups

* more fixes

* make format

* move nut19 to nuts directory

* `key` -> `privkey` and `pubkey`

* make format

* mint_info method for nut-19 support

* fix tests imports

* fix signature missing positional argument + fix db migration format not correctly escaped + pass in NUT-19 keypair to `request_mint` `request_mint_with_callback`

* make format

* fix `get_invoice_status`

* rename to xx

* nutxx -> nut20

* mypy

* remove `mint_quote_signature_required` as per spec

* wip edits

* clean up

* fix tests

* fix deprecated api tests

* fix redis tests

* fix cache tests

* fix regtest mint external

* fix mint regtest

* add test without signature

* test pubkeys in quotes

* wip

* add compat

---------

Co-authored-by: callebtc <93376500+callebtc@users.noreply.github.com>

cashu/core/nuts/nuts.py

@@ -0,0 +1,16 @@
+SWAP_NUT = 3
+MINT_NUT = 4
+MELT_NUT = 5
+INFO_NUT = 6
+STATE_NUT = 7
+FEE_RETURN_NUT = 8
+RESTORE_NUT = 9
+SCRIPT_NUT = 10
+P2PK_NUT = 11
+DLEQ_NUT = 12
+DETERMINSTIC_SECRETS_NUT = 13
+HTLC_NUT = 14
+MPP_NUT = 15
+WEBSOCKETS_NUT = 17
+CACHE_NUT = 19
+MINT_QUOTE_SIGNATURE_NUT = 20