PG write query timeouts

[suddendust]

Description

This PR sets query timeout for write APIs in FlatPostgresCollection.

Testing

Added an integration test

Checklist:

• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• Any dependent changes have been merged and published in downstream modules

[codecov]

Codecov Report

❌ Patch coverage is 94.44444% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 81.06%. Comparing base (c534f39) to head (128b206).

Files with missing lines	Patch %	Lines
...documentstore/postgres/FlatPostgresCollection.java	92.85%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #321      +/-   ##
============================================
+ Coverage     81.04%   81.06%   +0.01%     
- Complexity     1615     1617       +2     
============================================
  Files           243      243              
  Lines          7650     7656       +6     
  Branches        754      755       +1     
============================================
+ Hits           6200     6206       +6     
  Misses          960      960              
  Partials        490      490              

Flag	Coverage Δ
integration	81.06% <94.44%> (+0.01%)	⬆️
unit	57.15% <66.66%> (+0.03%)	⬆️

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[github-actions]

Test Results

  125 files  +1    125 suites  +1   38s ⏱️ -1s
  855 tests +3    854 ✅ +3  1 💤 ±0  0 ❌ ±0 
1 192 runs  +3  1 191 ✅ +3  1 💤 ±0  0 ❌ ±0 

Results for commit 128b206. ± Comparison against base commit c534f39.

[puneet-traceable]

Is this set per prepared statement? or is it possible to set it at connection?

[suddendust]

So it's a bit nuanced. There're three ways to do this:

1. Set it in PS - Like what we're doing here. In this case, the driver cancels the query by sending a new cancel request to the server.
2. Set it at a connection level - By setting SET statement_timeout = 60s in the connection pool config. However, this might pin connections at the proxy (using SET commands does but the doc is not very clear on whether SET statement_timeout will do this).
3. Set it in the RDS parameter group. This applies this timeout to any client regardless of what they've configured. Client can still use setQueryTimeout to set a value lesser than the global value in the param group.

Given our issues with pinning, I'll go with 1 + 3.