fix: COLLECT_LIST can now be applied to tables

[vcrfxia]

Description

Trying to apply the COLLECT_LIST UDAF to a table currently results in the error The aggregation function(s) (collect_list) cannot be applied to a table. This PR fixes the issue.

Testing done

Updated unit tests and added query translation tests.

Reviewer checklist

• Ensure docs are updated if necessary. (eg. if a user visible feature is being added or changed).
• Ensure relevant issues are linked (description should include text like "Fixes #")

[agavra]

Thanks @vcrfxia! I always learn something new about Java... I feel like changing the signature of the methods shouldn't have changed anything because the instantiation of the Udaf was still a TableUdaf. Where is the check happening to make sure that the given instance is a TableUdaf?

[vcrfxia]

Where is the check happening to make sure that the given instance is a TableUdaf?

@agavra here's the check:

ksql/ksql-engine/src/main/java/io/confluent/ksql/function/UdafTemplate.java

Lines 50 to 54 in 71ec1c0

	if (TableUdaf.class.isAssignableFrom(udaf.getReturnType())) {
	udafTypeSpec.superclass(GeneratedTableAggregateFunction.class);
	} else {
	udafTypeSpec.superclass(GeneratedAggregateFunction.class);
	}

[blueedgenick]

LGTM - thanks for fixing this up @vcrfxia !

[vcrfxia]

Closing in favor of #3104, which is identical except targeted at an earlier branch.