Allow option to specific CREATE INDEX to be CONCURRENTLY or NONCONCURRENTLY for target database YugabyteDB

[ssherwood]

Jira Link: DB-13446
YugabyteDB defaults index creation to CONCURRENTLY. This is most appropriate for on-line (live) migrations. However, for offline migrations, it may be desirable to have YugabyteDB use NONCONCURRENTLY instead.

This should be an optional configuration option when generating the CREATE INDEX output for YugabyteDB.

[hbhanawat]

@makalaaneesh is this issue still relevant?

[makalaaneesh]

With voyager 1.7.2, we changed the workflows to import indexes in the import schema step as opposed to import-schema --post-snapshot-import true step.

With this change, the indexes will be created at at time when there is no data present in the tables. Therefore, having the ability to create indexes NON-CONCURRENTLY is not relevant anymore.