implement /packages/{name} as its own route

A few things added with this commit:

- aurweb.packages.util
    - A module providing package and pkgbase helpers.
- aurweb.template.register_filter
    - A decorator that can be used to register a filter:
      @register_filter("some_filter") def f(): pass

Additionally, template partials have been split off a bit
differently. Changes:

- /packages/{name} is defined in packages/show.html.
- partials/packages/package_actions.html is now
  partials/packages/actions.html.
- partials/packages/details.html has been added.
- partials/packages/comments.html has been added.
- partials/packages/comment.html has been added.
- models.dependency_type additions: name and id constants.
- models.relation_type additions: name and id constants.
- models.official_provider additions: base official url constant.

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

test/test_packages_util.py

@@ -0,0 +1,51 @@
+import pytest
+
+from fastapi.testclient import TestClient
+
+from aurweb import asgi, db
+from aurweb.models.account_type import USER_ID, AccountType
+from aurweb.models.official_provider import OFFICIAL_BASE, OfficialProvider
+from aurweb.models.package import Package
+from aurweb.models.package_base import PackageBase
+from aurweb.models.user import User
+from aurweb.packages import util
+from aurweb.testing import setup_test_db
+
+
+@pytest.fixture(autouse=True)
+def setup():
+    setup_test_db(
+        User.__tablename__,
+        Package.__tablename__,
+        PackageBase.__tablename__,
+        OfficialProvider.__tablename__
+    )
+
+
+@pytest.fixture
+def maintainer() -> User:
+    account_type = db.query(AccountType, AccountType.ID == USER_ID).first()
+    yield db.create(User, Username="test_maintainer",
+                    Email="test_maintainer@examepl.org",
+                    Passwd="testPassword",
+                    AccountType=account_type)
+
+
+@pytest.fixture
+def package(maintainer: User) -> Package:
+    pkgbase = db.create(PackageBase, Name="test-pkg", Maintainer=maintainer)
+    yield db.create(Package, Name=pkgbase.Name, PackageBase=pkgbase)
+
+
+@pytest.fixture
+def client() -> TestClient:
+    yield TestClient(app=asgi.app)
+
+
+def test_package_link(client: TestClient, maintainer: User, package: Package):
+    db.create(OfficialProvider,
+              Name=package.Name,
+              Repo="core",
+              Provides=package.Name)
+    expected = f"{OFFICIAL_BASE}/packages/?q={package.Name}"
+    assert util.package_link(package) == expected