[CX] CONNECT bucket returns after initial ingestion

In DP2, the connect bucket statement returns immediately once the DCP connection is established.

The desired behavior is similar to the create index statement where the statement doesn't return until the state of all shadows reaches the DCP state for all vbucket as when the connect statement was submitted.

How can this be tested?

1. Create a bucket.
2. Create one of more shadows.
3. Connect the bucket.
4. Immediately run a query (count?) and the expected result should be returned.