Lease management settings should be consolidated in one place

[hongalex]

Currently, controlling min/max ack deadline is done in SubscriberOptions, but configuring the total extension (for a message's ack deadline) is in FlowControlOptions.

These are related settings and should be in the same place.

Separately, flow control options being in a the lease-manager.ts file seems strange, since lease management should only concern itself with modacks rather than flow/concurrency control.

[feywind]

As discussed elsewhere, the settings can't be changed until a breaking major. The lease manager changes are planned for an internals cleanup effort.

[feywind]

Kinda looks like the lease manager separation is going to help with this issue, too:

#1213

So I might do that sooner rather than later.