[Backport 2.16] [dataset-nav][bug] get connections by cluster and update client namespace

[opensearch-trigger-bot]

Backport d09895a from #7609.

[github-actions]

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[codecov]

Codecov Report

Attention: Patch coverage is 18.08511% with 77 lines in your changes missing coverage. Please review.

Project coverage is 63.74%. Comparing base (b423572) to head (529cf0a).

Files	Patch %	Lines
...taset_navigator/lib/catalog_cache/cache_manager.ts	0.00%	19 Missing ⚠️
...plugins/query_enhancements/server/utils/plugins.ts	5.26%	18 Missing ⚠️
.../public/ui/dataset_navigator/dataset_navigator.tsx	0.00%	11 Missing ⚠️
...taset_navigator/lib/catalog_cache/cache_loader.tsx	0.00%	10 Missing ⚠️
...navigator/lib/utils/fetch_external_data_sources.ts	11.11%	8 Missing ⚠️
...c/plugins/query_enhancements/server/utils/facet.ts	0.00%	6 Missing ⚠️
src/plugins/data/public/ui/settings/settings.ts	28.57%	5 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             2.16    #7611   +/-   ##
=======================================
  Coverage   63.73%   63.74%           
=======================================
  Files        3633     3631    -2     
  Lines       80088    80032   -56     
  Branches    12672    12667    -5     
=======================================
- Hits        51047    51013   -34     
+ Misses      25939    25917   -22     
  Partials     3102     3102           

Flag	Coverage Δ
Linux_1	30.54% <22.05%> (-0.03%)	⬇️
Linux_2	55.70% <ø> (ø)
Linux_3	40.60% <22.05%> (-0.02%)	⬇️
Linux_4	31.42% <18.08%> (-0.04%)	⬇️
Windows_1	30.56% <22.05%> (-0.03%)	⬇️
Windows_2	55.65% <ø> (ø)
Windows_3	40.59% <22.05%> (-0.04%)	⬇️
Windows_4	31.42% <18.08%> (-0.04%)	⬇️

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