fix: disable columnstore before BIGINT migration for TimescaleDB 2.17+
TimescaleDB 2.17+ requires explicitly disabling columnstore before
ALTER TABLE operations on hypertables, not just decompressing chunks.
The error "operation not supported on hypertables that have columnstore
enabled" occurs even after decompression.
Added Step 2 to disable columnstore with proper exception handling for
older TimescaleDB versions or non-hypertable scenarios.