[CALCITE-6314] Add RANDOM function (enabled in Postgres library)

[jduo]

[jduo]

@tanclary

[sonarqubecloud[bot]]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[jduo]

Looks like some merge conflicts?

Updated the PR. It's introduced from merging CALCITE-6278. I expect we'll see more of this since we have a few devs working on adding functions now.