cic-cache: Add tx tags in persistent storage

apps/cic-cache/cic_cache/db/migrations/default/versions/aaf2bdce7d6e_transaction_tags.py

@@ -0,0 +1,38 @@
+"""Transaction tags
+
+Revision ID: aaf2bdce7d6e
+Revises: 6604de4203e2
+Create Date: 2021-05-01 09:20:20.775082
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'aaf2bdce7d6e'
+down_revision = '6604de4203e2'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_table(
+            'tag',
+            sa.Column('id', sa.Integer, primary_key=True),
+            sa.Column('domain', sa.String(), nullable=True),
+            sa.Column('value', sa.String(), nullable=False),
+            )
+    op.create_index('idx_tag_domain_value', 'tag', ['domain', 'value'], unique=True)
+
+    op.create_table(
+            'tag_tx_link',
+            sa.Column('id', sa.Integer, primary_key=True),
+            sa.Column('tag_id', sa.Integer, sa.ForeignKey('tag.id'), nullable=False),
+            sa.Column('tx_id', sa.Integer, sa.ForeignKey('tx.id'), nullable=False),
+                )
+
+def downgrade():
+    op.drop_table('tag_tx_link')
+    op.drop_index('idx_tag_domain_value')
+    op.drop_table('tag')