Support adding or updating index definitions via oak-run

Currently oak-run can be used to reindex an existing index present in NodeStore. I would like to extend this feature set to support adding or updating the index definition and then reindexing them. The end user story would be like below

Development team updates or introduces a new index definition and gives it to system admin. Then admin can use oak-run and give it reference to the index definition and then tooling takes care of indexing (with read only mode) and then importing the updated index definition back into the repository.

To start with the index definitions would be provided as a json file with a single json file containing index definitions which needs to be reindexed. The file format would be similar to one we used for dumping index definition (OAK-6224).