[Feature][Spark] Add deletion vector metrics in Merge

[andreaschat-db]

Feature request

Which Delta project/connector is this regarding?

• [x] Spark
• [ ] Standalone
• [ ] Flink
• [ ] Kernel
• [ ] Other (fill in here)

Overview

This issue is a follow up of the recent implementation of Deletion Vectors in Merge (https://github.com/delta-io/delta/issues/2296). Merge needs to report deletion vector metrics similarly with UPDATE and DELETE commands.

Willingness to contribute

The Delta Lake Community encourages new feature contributions. Would you or another member of your organization be willing to contribute an implementation of this feature?

• [x] Yes. I can contribute this feature independently.
• [ ] Yes. I would be willing to contribute this feature with guidance from the Delta Lake community.
• [ ] No. I cannot contribute this feature at this time.

[felipepessoto]

I believe this is done.

BTW do we have metrics for reads?