[ENG-2760] Merge id and name arguments into one for `client.flow()`

[kenxu95]

To fetch by name, I have to use client.flow(flow_name="…"), which is quite redundant. Let's just use the signature def flow(self, flow_identifier)

_{From SyncLinear.com | ENG-2760}

[sravoor]

@jpurusho65 focus on the GKE project first and then come back to these tasks

[vsreekanti]

@jpurusho65 @sravoor, this should be super quick, so let's tackle it in next week's on call work.

[jpurusho65]

Sure will take care of this

[sravoor]

from @saurav-c on slack:

won’t this break existing notebooks that are using named arguments for flow_id or flow_name, since they’re being replaced by flow_identifier? Should we roll out this API change more gradually and give a deprecation warning?

@vsreekanti @kenxu95 @jpurusho65 ^^^^

[vsreekanti]

Yes, 100% agree with Saurav.

[kenxu95]

Should we reopen this task then? @sravoor

[kenxu95]

Created the new task ENG-3007

[jpurusho65]

I changed the API's to be backward compatible, and created another task ENG-3013 to track complete removal of the deprecated parameters in a future release. The API now throws a deprecated warning to end user. PR is out for review, will be checked in shortly.