Bug 35783: Replace TT plugin's method Biblio::RecallsCount

Bug 35783: Replace TT plugin's method Biblio::RecallsCount

We can use biblio.recalls.search( completed => 0 ).count instead.

Test plan:
1. Go to the biblio detail view, click on the different entries in the menu
on the left. Confirm that the "Recalls" tab always has the correct number
of current recalls display in the parenthesis.

2. Run a search and confirm that the number of current recalls are still displayed
for each result.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>