chore: set maxIdleConns for jobsdb handles and emit (*sql.DB).Stats

[Sidddddarth]

Description

1. Set maxIdleConns for all the jobsdb handles.
   The current default is only 2 max idle conns per pool which causes a lot of turnaround and consistent new connections. Setting it to the same as max open connections.
2. Emit periodic (*sql.DB).Stats(). that gauge the total closed(due to maxIdleConns) every 15 seconds(configurable).
3. Add tablePrefix to the jobsdb connection pool's application_name.

Linear Ticket

Security

• The code changed/added as part of this pull request won't create any security issues with how the software is being used.

[codecov]

Codecov Report

Attention: Patch coverage is 96.00000% with 2 lines in your changes missing coverage. Please review.

Please upload report for BASE (release/1.34.x@53386d6). Learn more about missing BASE report.
Report is 1 commits behind head on release/1.34.x.

Files with missing lines	Patch %	Lines
jobsdb/jobsdb.go	96.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@                Coverage Diff                @@
##             release/1.34.x    #5123   +/-   ##
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  Coverage                  ?   73.02%           
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  Files                     ?      435           
  Lines                     ?    50477           
  Branches                  ?        0           
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  Hits                      ?    36862           
  Misses                    ?    11207           
  Partials                  ?     2408           

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