De-duplicate Backup/Restore logic (#3311)

* De-duplicate Backup/Restore logic

Create internal _do_backup()/_do_restore() method which de-duplicates
some of the backup/restore logic previously part of full/partial backup/restore.

* Add Backup/Restore test coverage

tests/backups/conftest.py

@@ -0,0 +1,46 @@
+"""Mock test."""
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from supervisor.backups.const import BackupType
+from supervisor.backups.validate import ALL_FOLDERS
+
+from tests.const import TEST_ADDON_SLUG
+
+
+@pytest.fixture(name="backup_mock")
+def fixture_backup_mock():
+    """Backup class mock."""
+    with patch("supervisor.backups.manager.Backup") as backup_mock:
+        backup_instance = MagicMock()
+        backup_mock.return_value = backup_instance
+
+        backup_instance.store_addons = AsyncMock(return_value=None)
+        backup_instance.store_folders = AsyncMock(return_value=None)
+        backup_instance.restore_addons = AsyncMock(return_value=None)
+        backup_instance.restore_folders = AsyncMock(return_value=None)
+        backup_instance.restore_repositories = AsyncMock(return_value=None)
+
+        yield backup_mock
+
+
+@pytest.fixture
+def partial_backup_mock(backup_mock):
+    """Partial backup mock."""
+    backup_instance = backup_mock.return_value
+    backup_instance.sys_type = BackupType.PARTIAL
+    backup_instance.folders = []
+    backup_instance.addon_list = [TEST_ADDON_SLUG]
+    yield backup_mock
+
+
+@pytest.fixture
+def full_backup_mock(backup_mock):
+    """Full backup mock."""
+    backup_instance = backup_mock.return_value
+    backup_instance.sys_type = BackupType.FULL
+    backup_instance.folders = ALL_FOLDERS
+    backup_instance.addon_list = [TEST_ADDON_SLUG]
+    yield backup_mock