feat(editor/subscriber): Show counter for Subscriber Plugins (Logical Nodes / Later) (GOOSE/SMV)

[dlabordus]

This will replace PR #993 and closes #958

Thanks @danyill for the code.

It will added the counter to the Left Side of the Editor for both Data and Later Binding.
Through a event the counter will be updated if the subscription changes.

[dlabordus]

@danyill, which issue will this PR close? Would be nice to link it to this PR.

I think I got all your code from the other PR.

[danyill]

@danyill, which issue will this PR close? Would be nice to link it to this PR.

I think I got all your code from the other PR.

Added to the first comment, #958. Thanks.

[danyill]

Thank you for reviewing, tidying up and improving my efforts 👏

There is a one liner we must fix as this PR breaks the indexing completely:

• I tested with IOP_2019_HV_v9_ed2.1.scd, I found that it takes 5-10 seconds to update when I click on an FCDA in the GOOSE later-binding plugin for every different FCDA I select.
• In my branch issue-958-number-of-connections it only seems to happen for the first one (as I would expect).

We reset the map where we should not, I have identified the place where it occurs.

[dlabordus]

@danyill, can you try again if the performance is better?

I fixed the update method. This was indeed needed to make it faster.

[danyill]

LVGTM, thanks!