Integrate websocket client into rails side

[ShiningRay]

And remove the usage of PoolTransactionEntry, instead using CkbTransaction.tx_pending.

[codecov-commenter]

Codecov Report

Patch coverage: 37.13% and project coverage change: -1.64 ⚠️

Comparison is base (92915ff) 60.25% compared to head (7876698) 58.62%.

❗ Current head 7876698 differs from pull request most recent head a15a626. Consider uploading reports for the commit a15a626 to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1282      +/-   ##
===========================================
- Coverage    60.25%   58.62%   -1.64%     
===========================================
  Files          267      267              
  Lines         7579     7103     -476     
===========================================
- Hits          4567     4164     -403     
+ Misses        3012     2939      -73     

Impacted Files	Coverage Δ
app/controllers/api/v2/transactions_controller.rb	0.00% <0.00%> (ø)
app/models/cell_datum.rb	0.00% <ø> (ø)
app/models/deployed_cell.rb	10.52% <0.00%> (-61.85%)	⬇️
app/models/rolling_avg_block_time.rb	0.00% <0.00%> (ø)
...orkers/address_unclaimed_compensation_generator.rb	0.00% <0.00%> (ø)
app/workers/flush_inputs_outputs_cache_worker.rb	0.00% <0.00%> (-100.00%)	⬇️
app/workers/pool_transaction_check_worker.rb	0.00% <0.00%> (-29.17%)	⬇️
lib/scheduler.rb	0.00% <0.00%> (ø)
lib/tasks/migration/fill_nrc_721_token.rake	7.35% <0.00%> (-0.46%)	⬇️
lib/websocket.rb	0.00% <0.00%> (ø)
... and 22 more

... and 11 files with indirect coverage changes

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