Unify pagination markup and styling

[slomo]

Currently there are different ways to limit pagination and also different markup and styling for the project_list, organisation_list and idea_list views. They should probably be all the same.

[mkind]

Maybe redundant to https://github.com/liqd/a4-opin/issues/1016

[hello-kathi]

@phillimorland dev thingy? decide if closing ;)

[philli-m]

use pagination.html in organisation_list and project_list