feat: allow users to hide deleted comments

Closes: #435

Signed-off-by: Leonidas Spyropoulos <artafinde@archlinux.org>

migrations/versions/e4e49ffce091_add_hidedeletedcomments_to_user.py

@@ -0,0 +1,33 @@
+"""Add HideDeletedComments to User
+
+Revision ID: e4e49ffce091
+Revises: 9e3158957fd7
+Create Date: 2023-04-19 23:24:25.854874
+
+"""
+from alembic import op
+from sqlalchemy.exc import OperationalError
+
+from aurweb.models.user import User
+
+# revision identifiers, used by Alembic.
+revision = "e4e49ffce091"
+down_revision = "9e3158957fd7"
+branch_labels = None
+depends_on = None
+
+table = User.__table__
+
+
+def upgrade():
+    try:
+        op.add_column(table.name, table.c.HideDeletedComments)
+    except OperationalError:
+        print(
+            f"Column HideDeletedComments already exists in '{table.name}',"
+            f" skipping migration."
+        )
+
+
+def downgrade():
+    op.drop_column(table.name, "HideDeletedComments")