simplify environment variables required.

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.

lnbits/extensions/diagonalley/crud.py

@@ -1,7 +1,7 @@
 from base64 import urlsafe_b64encode
 from uuid import uuid4
 from typing import List, Optional, Union
-import requests
+import httpx
 from lnbits.db import open_ext_db
 from lnbits.settings import WALLET
 from .models import Products, Orders, Indexers
@@ -120,7 +120,7 @@ def get_diagonalleys_indexer(indexer_id: str) -> Optional[Indexers]:
     with open_ext_db("diagonalley") as db:
         roww = db.fetchone("SELECT * FROM indexers WHERE id = ?", (indexer_id,))
     try:
-        x = requests.get(roww["indexeraddress"] + "/" + roww["ratingkey"])
+        x = httpx.get(roww["indexeraddress"] + "/" + roww["ratingkey"])
         if x.status_code == 200:
             print(x)
             print("poo")
@@ -158,7 +158,7 @@ def get_diagonalleys_indexers(wallet_ids: Union[str, List[str]]) -> List[Indexer
 
         for r in rows:
             try:
-                x = requests.get(r["indexeraddress"] + "/" + r["ratingkey"])
+                x = httpx.get(r["indexeraddress"] + "/" + r["ratingkey"])
                 if x.status_code == 200:
                     with open_ext_db("diagonalley") as db:
                         db.execute(