persist pagination size for list/grid views

Summary: Uses localStorage to persist page size. Stores different values for List & Grid views since their pagination sizes are different. Fixes T778.

Test Plan: Try setting pagination sizes of various list & grid views, switching between them, refreshing pages, clearing localStorage

Reviewers: rjmackay, shadowhand

Reviewed By: rjmackay, shadowhand

Maniphest Tasks: T778

Differential Revision: https://phabricator.ushahidi.com/D364