support user incremental predicates on merge

[dave-connors-3]

Describe the feature

Users should be able to supply incremental models with arbitrary predicates during the merge step to prevent unnecessary table scan for massive data sets.

Describe alternatives you've considered

None

Additional context

See:

• Core Issue 5680
• Core Issue 3293
• Core PR 5702

Who will this benefit?

users with extremely large datasets who want to limit the scan of their merge operations on incremental models!

Are you interested in contributing this feature?

Yes

[bilalaslamseattle]

@ueshin @superdupershant seems like a reasonable ask since it's supported in other DWs.