res_pjsip_pubsub: Persist subscription 'generator_data' in sorcery

Fixes #895

(cherry picked from commit 3243316dac)

contrib/ast-db-manage/config/versions/801b9fced8b7_add_generator_data_to_ps_subscription_.py

@@ -0,0 +1,24 @@
+"""add generator_data to ps_subscription_persistence
+
+Revision ID: 801b9fced8b7
+Revises: 655054a68ad5
+Create Date: 2024-09-23 16:44:55.360055
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '801b9fced8b7'
+down_revision = '655054a68ad5'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    with op.batch_alter_table('ps_subscription_persistence') as batch_op:
+        batch_op.add_column(sa.Column('generator_data', sa.UnicodeText))
+
+
+def downgrade():
+    with op.batch_alter_table('ps_subscription_persistence') as batch_op:
+        batch_op.drop_column('generator_data')