This PR unites all the managment links so they use the same code to
open and close the underlying link. As part of this a few nice
refactors were able to happen:

1. All link related classes, including the mgmt link, now use the same
init() code (which also means they can, if passed, handle abortSignal's
when running)
2. open/close state has been moved into LinkEntity.
3. Boundaries between LinkEntity and the child classes is more clear.

…ut still allow the link to be reopened.

…verride in child classes.

…loseInitiated only reflected the user calling .close()).

* Adding in unit tests for LinkEntity

…rying to add credits when the receiver is closed).

Should help catch bugs.

- change the close originator to a close mode and now it's "permanently" or "linkonly".
- Rename the _'d elements to make them normal methods but then marked them as protected. This works fine since the classes aren't actually used in the public API.

… Not a big deal but no reason to do it either.

…now rather than wait for the .close() call to complete.

…eted (no longer used by child classes).

* Remove the last calls that were still in the management client (they're all taken care of by LinkEntity.initLink() now)

…h is causing a timer to be created (and this requires us to properly close the clients we create).

… the link object it while we were initializing. If so it throws an error.

Co-authored-by: Ramya Rao <ramya.rao.a@outlook.com>

…ing the session receiver.

…nitiating the close. They do all result in the same thing (link can't be reopened) but it's best to leave it open in the message.

…' of https://github.com/richardpark-msft/azure-sdk-for-js into richardpark-sb-track2-refactor-streamingreceiver-2-lite

… in log messages. Also, updated so we use the appropriate logger for each receiver type so users can still filter as they did before.

…ight as well make that official. :)

public fields, protected fields, private fields
constructor
public methods/properties, protected methods/properties, private methods/properties

…(the logging in _initLink() has been improved and absorbed it).

Biggest conflicts were just around the new/renamed objects for
parameters when creating and subscribing to sessions.

Co-authored-by: Harsha Nalluru <sanallur@microsoft.com>

Co-authored-by: Harsha Nalluru <sanallur@microsoft.com>

… specify the same partition key as session id.

…zed (they both check it). So we can get rid of the outer check.

…ink check properly)

…entity

…_isOpen()

* Remove some redundant isOpen() calls (for instance, in closeLink)
* Remove redundant call to clear the token renewal timer in the management link in favor of the one that's already occuring in LinkEntity. That was the last non-linkEntity usage so I was able to make the timer private.

…ving a comment inline to explain why mgmt client is different.

…accessor)

- Use wasClosedPermanently in the Sender.