[Issue tracker] make Batch mode visible only with developer permission

[christinerogers]

Top-priority followup from #9339, spun out of #9418

Batch mode be visible to all who can see the module, as it is currently.
It's designed for the dev/DCC team to handle and update issues -- End Users of Loris shouldn't be able to see / use Batch mode.

what to do:

• Hide the Batch Mode button unless the user has issue_tracker_developer permission

Consider doing #9423 at the same time - correct the button style

If time / nice to have: make sure the batch page doesn't load if the user doesn't have issue_tracker_developer

This solves the requirement for a permission restricting access, clearly defined in the original issue, and it was simply not done yet.
I don't want this to block #9339 but it is still important and should be the next PR after #9339.

@ay-bh please follow up with @racostas to ensure we are addressing this as a priority next PR, thank you very much

[regisoc]

Thanks for this @christinerogers ! As it is a new feature that we will experiment on, maybe starting with a new permission for beta testing might be more suited. What do you think @racostas @christinerogers @ay-bh ?

[christinerogers]

I think the minimum necessary here for Nov 1 is that it be governed by an existing permission, and I think the one I specified suffices for now.
This means Ayush only to add 1-2 lines of code (if condition on the button) instead of a schema change, patch etc.

@regisoc -- in case Ayush has more time, could you elaborate on which group of users you think aren't included/excluded with the 'developer' permission? (It's really a DCC permission, coordinators get it too)

[christinerogers]

@ay-bh tips for getting started:
Look at how buttons are disabled/hidden in other modules depending on a user permission -- Here's an example

• Show/hide Proband button in the Candidate module

Consider doing at the same time #9423