feat(guardian-prover-health-check): add indexer in MySQL

[xiaodino]

To optimize these queries which introduce high load based on database monitoring

SELECT * FROM `health_checks` WHERE `guardian_prover_id` = ? ORDER BY `created_at` DESC LIMIT ?

SELECT COUNT ( * ) FROM `health_checks` WHERE `guardian_prover_id` = ? AND `created_at` > NOW ( ) - INTERVAL ? SQL_TSI_DAY

SELECT * FROM `signed_blocks` WHERE `block_id` >= ?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (b00d0b1) 26.82% compared to head (6516243) 26.82%.
Report is 9 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #15945   +/-   ##
=======================================
  Coverage   26.82%   26.82%           
=======================================
  Files         105      105           
  Lines        6188     6188           
=======================================
  Hits         1660     1660           
  Misses       4348     4348           
  Partials      180      180           

Flag	Coverage Δ		*Carryforward flag
eventindexer	17.22% <ø> (ø)		Carriedforward from b00d0b1
guardian-prover-health-check	34.81% <ø> (ø)
relayer	37.88% <ø> (ø)		Carriedforward from b00d0b1

*This pull request uses carry forward flags. Click here to find out more.

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