JingDas

The `RelOptForeignKey` component has been added to represent the composite or single foreign key and the unique constraint that foreign key references. Sorry to bother you, @asolimando @julianhyde would you...

> > The `RelOptForeignKey` component has been added to represent the composite or single foreign key and the unique constraint that foreign key references. Sorry to bother you, @asolimando @julianhyde...

Sorry, it was closed by mistake，I reopen it and fixed the most necessary SonarCloud detected code.

I some confusion about the failed results of the CI tests. CI failed test log as fllowing: ``` org.apache.calcite.test.RelOptRulesTest > testProjectJoinRemove25() failure marker FAILURE 0.0sec, org.apache.calcite.test.RelOptRulesTest > testProjectJoinRemove25() java.lang.AssertionError: Expected...

Aha! It seems calcite main code change, And the CI seems to use the new [main logic](https://github.com/apache/calcite/blob/3ab8003106507b1664ad2c42860789776a816cd3/testkit/src/main/java/org/apache/calcite/test/RelOptFixture.java#L394C1-L400C45). I will fix it according to main code usage.

> Aha! It seems calcite main code change, And the CI seems to use the new [main logic](https://github.com/apache/calcite/blob/3ab8003106507b1664ad2c42860789776a816cd3/testkit/src/main/java/org/apache/calcite/test/RelOptFixture.java#L394C1-L400C45). I will fix it according to main code usage. Have fixed it.

The code has been ready, I will be very grateful if someone can help me review the code