test: restructure tests (#2444)

unit, api, wallets
* only run test-api for migration

tests/api/test_public_api.py

@@ -0,0 +1,26 @@
+import pytest
+
+
+# check if the client is working
+@pytest.mark.asyncio
+async def test_core_views_generic(client):
+    response = await client.get("/")
+    assert response.status_code == 200
+
+
+# check GET /public/v1/payment/{payment_hash}: correct hash [should pass]
+@pytest.mark.asyncio
+async def test_api_public_payment_longpolling(client, invoice):
+    response = await client.get(f"/public/v1/payment/{invoice['payment_hash']}")
+    assert response.status_code < 300
+    assert response.json()["status"] == "paid"
+
+
+# check GET /public/v1/payment/{payment_hash}: wrong hash [should fail]
+@pytest.mark.asyncio
+async def test_api_public_payment_longpolling_wrong_hash(client, invoice):
+    response = await client.get(
+        f"/public/v1/payment/{invoice['payment_hash'] + '0'*64}"
+    )
+    assert response.status_code == 404
+    assert response.json()["detail"] == "Payment does not exist."