feat: improve on api structure, add openapi tags (#2295)

this logically groups api endpoints and gioves them specific openapi tags. which makes them nice on the `/docs` endpoint and makes the `api.py` more approachable
* add wallets list endpoint
* remove trailing slashes from endpoints
* fixup topup url
* fix trailing slash on auth
* backwards compatibility

tests/core/views/test_admin_api.py

@@ -5,13 +5,13 @@ from lnbits.settings import settings
 
 @pytest.mark.asyncio
 async def test_admin_get_settings_permission_denied(client, from_user):
-    response = await client.get(f"/admin/api/v1/settings/?usr={from_user.id}")
+    response = await client.get(f"/admin/api/v1/settings?usr={from_user.id}")
     assert response.status_code == 401
 
 
 @pytest.mark.asyncio
 async def test_admin_get_settings(client, superuser):
-    response = await client.get(f"/admin/api/v1/settings/?usr={superuser.id}")
+    response = await client.get(f"/admin/api/v1/settings?usr={superuser.id}")
     assert response.status_code == 200
     result = response.json()
     assert "super_user" not in result
@@ -21,7 +21,7 @@ async def test_admin_get_settings(client, superuser):
 async def test_admin_update_settings(client, superuser):
     new_site_title = "UPDATED SITETITLE"
     response = await client.put(
-        f"/admin/api/v1/settings/?usr={superuser.id}",
+        f"/admin/api/v1/settings?usr={superuser.id}",
         json={"lnbits_site_title": new_site_title},
     )
     assert response.status_code == 200
@@ -34,7 +34,7 @@ async def test_admin_update_settings(client, superuser):
 @pytest.mark.asyncio
 async def test_admin_update_noneditable_settings(client, superuser):
     response = await client.put(
-        f"/admin/api/v1/settings/?usr={superuser.id}",
+        f"/admin/api/v1/settings?usr={superuser.id}",
         json={"super_user": "UPDATED"},
     )
     assert response.status_code == 400