change(python): move request & pkgbase request routes

Move package request routes and related routes to their
respective routers. In addition, move some utility used
for requests over from `aurweb.packages`.

Introduced routers:
- `aurweb.routers.requests`

Introduced package:
- `aurweb.requests`

Introduced module:
- `aurweb.requests.util`

Changes:
- Moved `aurweb.packages.validate` to `aurweb.pkgbase.validate`
- Moved requests listing & request closure routes to
  `aurweb.routers.requests`
- Moved pkgbase request creation route to `aurweb.routers.pkgbase`
- Moved `get_pkgreq_by_id` from `aurweb.packages.util` to
  `aurweb.requests.util` and fixed its return type hint.

Signed-off-by: Kevin Morris <kevr@0cost.org>

test/test_packages_util.py

@@ -2,7 +2,6 @@ from datetime import datetime
 
 import pytest
 
-from fastapi import HTTPException
 from fastapi.testclient import TestClient
 
 from aurweb import asgi, config, db
@@ -98,11 +97,6 @@ def test_query_notified(maintainer: User, package: Package):
     assert query_notified[package.PackageBase.ID]
 
 
-def test_pkgreq_by_id_not_found():
-    with pytest.raises(HTTPException):
-        util.get_pkgreq_by_id(0)
-
-
 def test_source_uri_file(package: Package):
     FILE = "test_file"