feat: Add core-data postgres reading db client methods

[lindseysimple]

Relates to #4847. Add core-data reading related db client methods for postgres client.

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[lindseysimple]

@cloudxxx8 PR's ready for review, thanks.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[cloudxxx8]

LGTM