Fix Continuous Aggregate migration policies

[fabriziomello]

After migrate a Continuous Aggregate from the old format to the new using cagg_migrate procedure we end up with the following problems:

• Refresh policy is not copied from the OLD to the NEW cagg;
• Compression setting is not copied from the OLD to the NEW cagg.

Fixed it by properly copying the refresh policy and setting the timescaledb.compress=true flag to the new CAGG.

Fix #4710

[codecov[bot]]

Codecov Report

Merging #4713 (f304a2d) into main (042735f) will decrease coverage by 0.02%. The diff coverage is 92.59%.

@@            Coverage Diff             @@
##             main    #4713      +/-   ##
==========================================
- Coverage   90.91%   90.89%   -0.03%     
==========================================
  Files         224      224              
  Lines       42419    42332      -87     
==========================================
- Hits        38567    38479      -88     
- Misses       3852     3853       +1     

Impacted Files	Coverage Δ
src/compat/compat.h	93.87% <ø> (+0.89%)	:arrow_up:
src/planner/expand_hypertable.c	93.77% <88.23%> (-0.18%)	:arrow_down:
src/bgw/job.c	94.41% <100.00%> (-0.17%)	:arrow_down:
tsl/src/compression/api.c	95.70% <100.00%> (ø)
tsl/src/compression/compression.c	95.26% <100.00%> (+0.01%)	:arrow_up:
tsl/src/nodes/gapfill/gapfill_plan.c	96.87% <100.00%> (ø)
src/loader/bgw_message_queue.c	85.52% <0.00%> (-2.64%)	:arrow_down:
src/loader/bgw_launcher.c	89.24% <0.00%> (-2.54%)	:arrow_down:
src/import/planner.c	62.50% <0.00%> (-1.81%)	:arrow_down:
src/bgw/job_stat.c	86.85% <0.00%> (-0.47%)	:arrow_down:
... and 18 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 2529ae3...f304a2d. Read the comment docs.