fix: do not allow implicit casting in UDAF function lookup

[agavra]

Description

fixes #5129

ensures that lookups for UDAFs in the UdfIndex do not support implicit casting. Previously, the UDF index would find a match but it would fail later on with a cryptic error message.

Testing done

Unit testing and end to end testing:

ksql> SELECT COLLECT_LIST(amount) FROM transactions GROUP BY rowkey EMIT CHANGES;
Function 'collect_list' does not accept parameters (DECIMAL(12, 2)).
Valid alternatives are:
collect_list(BOOLEAN val)
collect_list(DOUBLE val)
collect_list(INT val)
collect_list(BIGINT val)
collect_list(VARCHAR val)
For detailed information on a function run: DESCRIBE FUNCTION <Function-Name>;

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 #")

[spena]

lgtm

[MichaelDrogalis]

Nice one :)