Showing total number of subscriptions.

Checklist

• I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• I have read the contribution guidelines given at https://github.com/TeamNewPipe/NewPipe/blob/HEAD/.github/CONTRIBUTING.md.
• This issue contains only one feature request. I will open one issue for every feature I want to request.

Describe the feature you want

Since there is problem #5806, #6290. I think it would be better to show a Toast message/Snackbar while importing subscriptions like Total Subscriptions imported= {}. So that people, at the time of importing, can compare the total items imported in NewPipe vs total subscriptions shown in actual youtube app/website and know if the subscriptions has been totally loaded.

Also, after implementing this #5960, showing total no of subscriptions alongside the service will be beneficial too (Even if above Toast message or Snackbar is missed by user at that time)

Is your feature request related to a problem? Please describe it

Yes I filed this issue #6290, and there was this issue too #5806

Additional context

How will you/everyone benefit from this feature?

In future, even if there is problem with google takeout or NewPipe's json parsing algorithm, people can instantly know about the problem at the time of importing.