Add redirection awareness for MERGE

[findinpath]

Description

Add redirection awareness for the task:

• MERGE INTO target USING source

Is this change a fix, improvement, new feature, refactoring, or other?

This is a fix.

Is this a change to the core query engine, a connector, client library, or the SPI interfaces? (be specific)

This is a core engine change affecting mainly hive/iceberg connectors.

How would you describe this change to a non-technical end user or system administrator?

In the context of dealing with a shared Hive Metastore Service where tables of different types can co-exist in the metastore, it is helpful for the end-user to perform automatically table redirections when the user is in the context of a hive schema, but is referencing an iceberg table.

Related issues, pull requests, and links

Documentation

(x) No documentation is needed.
( ) Sufficient documentation is included in this PR.
( ) Documentation PR is available with #prnumber.
( ) Documentation issue #issuenumber is filed, and can be handled later.

Release notes

( ) No release notes entries required.
(x) Release notes entries required with the following suggested text:

# Core
* Add redirection awareness for `MERGE` operation. ({issue}`14055`)

[findepi]

nit: you can put ON on the previous like, just like you would usually do with a JOIN

[findepi]

checkstyle should error here

[findepi]

i see it didn't, but we have a rule that disallows whitespace before ), right?

[findinpath]

I think you are hinting at airlift/airbase#323
I can convert the text block to a string concat construct.

[findepi]

I think you are hinting at airlift/airbase#323

no

I can convert the text block to a string concat construct.

no need to.

the )) should be on the previous line though

[findinpath]

CI failure on suite-2 is a timeout failure.

[phd3]

#14055 (comment) seems unaddressed, but lgtm. will merge if @findepi doesn't feel too strongly.

[findepi]

i don't feel strongly about that one, thank you @phd3

[phd3]

Merged, thanks!

[colebow]

I'm not sure the proposed release note works here... if the template says we're fixing something, what are we fixing / what impact will the end user see? And even if it's a change to the core engine, if it only affects Hive/Iceberg, should we just list the note in those sections?

cc @findepi @phd3