Issue #84: Paginate Actions

Addresses #84 
Added generic getPaginationData() function for findAndCountAll results.
Moved .get('/actions') logic to showActions() function.
Extend templateData in showBlocks() and showActions() with paginationData.
I temporarily reverted perPage to 5000 for blocks because there's still no way to block all that includes off-page users, so this allows 'Block all' to work usefully for more lists (where 500 per page would mean 'Block all' frequently misses a lot). For Actions that doesn't apply, so let's go with 500 per page here.

Eventually I want to do some condensing and grouping so, e.g. cancelled Actions are not shown by default, and bulk blocks get grouped into a single expandable row. Then 500 per page can really show some useful stuff. But that's for another time.