Bucket rewrite: able to mark original blocks for deletion after new blocks are created

[yeya24]

Is your proposal related to a problem?

Bucket rewrite tool supports block deletion and relabeling. It creates a new block and the original block is left unchanged. Usually, the old block can be removed. But it requires another step to mark the original block.

Describe the solution you'd like

It would be handy to have a flag to mark the original blocks for deletion after the new blocks created successfully. This flag should work only in none dry run mode.

[yeya24]

Thoughts? @bwplotka @onprem @GiedriusS

[GiedriusS]

Makes total sense. For some reason I thought that we were doing this automatically already

[yeya24]

Assign this myself.

[GiedriusS]

Fixed in #4392.