ARR: Add new tab to keep track of maximum load across tracks

[haroldrubio]

ARR needs to be able to quickly see in a table if they have enough reviewer/AC capacity, and also have a breakdown of this by track. This will be an extra tab, most likely just enabled by setting a flag in the PC console webfield

[melisabok]

We would need to show the custom quota for each reviewer/AC, what about showing it in the Reviewer and AC status tabs? below to each reviewer name.

In the overview tab we can show the sum of all the quotas so PCs can decide if they have enough reviewers/AC.

About breaking this down by track, is this really needed if they are going to run only one matching?

cc @xkopenreview