Output the correct people counts on the organisation house page

Previously these were just the counts for all positions, rather than
filtering down. We're loosing "National Executive" as it's too tricky
trying to filter members down by positions.
Add filters for "All members" and "Office bearers" to org people
Change member wording on the org people page

'member' is a specific position within houses, so I've changed the
wording to use 'people' instead to remove the ambiguity.
Change order of filters on org people page

This matches the order on organisation house pages.
Fix active classes on the organisation people page

Make sure the active class is based on the correct variable in GET.
Merge branch 'issues/899-organisation-house-people-totals'