[CALCITE-6584] Validate prefixed column identifiers in SET clause of UPDATE statement

[nielspardon]

This PR adds validation of prefixed column identifiers in SET clause of UPDATE statement (and in the UPDATE statement within a MERGE statement)

• This is a follow-up PR to [CALCITE-6576] SqlParser: allow using table alias with column identifiers in SET section of UPDATE statement #3959
• I first had to change SqlValidatorUtil.addFields() to use the Util.last() method for getting the last element of a compound identifier instead of relying on simple identifiers
• I then implemented a validation logic in SqlValidatorImpl.createTargetRowType() which is being used for validating INSERT, UPDATE and MERGE
• in presence of the new targetTableAlias parameter the validation logic checks the prefix of any non-simple identifiers or in other words it checks that any prefixed column identifiers are prefixed with the target table alias
• I tried to check for any existing validation logic that I could reuse and it's possible I might have missed a utility method that I could have used.
• The validation logic supports a mix of prefixed and unprefixed columns in the SET clause. Not sure if I should only allow prefixed columns here.

Let me know your thoughts.

[sonarcloud]

Quality Gate passed

Issues
8 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

[caicancai]

LGTM

[mihaibudiu]

postgres actually rejects this: Query Error: error: column "e" of relation "emp" does not exist