Preserve LATERAL UNNEST during SqlNode validation

[KevinGe00]

Summary

This is a follow up to #98, where LATERALs were only preserved during validation if they appeared in the form ... LATERAL (SELECT ..... This PR induces the preservation behavior also in the .. LATERAL (UNNEST ... case, this is needed for Coral to produce correct translations on views (see CoralSqlNodeToSparkSqlNodeConverter for details).

Testing

• new unit test to test that this only a preservation mechanism, we never add LATERALs that were never there to begin with
  • note that we cannot write a LATERAL UNNEST test case here in Calcite since it will not parse, see here. Instead we will use an acompanying Coral unit test that will generate the LATERAL UNNEST sqlnode case we need to test
• new unit test in coral with these changes: Bump Calcite to preserve LATERALs in LATERAL UNNEST calls coral#542
• mvn clean build (also runs all unit tests) ./mvnw clean install -Dgpg.skip -f core/pom.xml
• clean build in coral with these changes ./gradlew clean build
• correct translation with these changes for production view text which was previously incorrect
• regression testing on all production views [pending]

[KevinGe00]

This was incorrect, we want to recurse into same function (validateFrom) and not into validateQuery.

[KevinGe00]

This is needed to work correctly with Coral's HiveSqlToRelConverter class which extends this class and overrides this function.

[aastha25]

@KevinGe00 in general (1) lets add the commands used to build & test, especially how to i-test with Coral, in the PR description. it helps build confidence in the changes and it'll be useful for future work as well. (2) Please file the Coral PR and cross reference it here so that reviewers can follow testing done related to new unit test in coral with these changes

[KevinGe00]

@KevinGe00 in general (1) lets add the commands used to build & test, especially how to i-test with Coral, in the PR description. it helps build confidence in the changes and it'll be useful for future work as well. (2) Please file the Coral PR and cross reference it here so that reviewers can follow testing done related to new unit test in coral with these changes

i-testing with Coral can only be done after merging and publishing these changes, then using the newest Calcite version containing these changes in a Coral feature branch in the regression pipeline, same thing done for #98.

[aastha25]

Approving to unblock i-testing. Let's revisit the code changes of this PR during / after the i-testing.