Members are shown according to cohort

One-sentence description

The current way of displaying members when you select all members, is by showing them on cohort order, while this should change to alphabetical order.

Why?

It is more clear when it is sorted on alphabetical order, instead of first sorted on Cohort order and then alphabetical order.

Current implementation

Currently, it is sorted on Cohort order, and then Alphabetical order, when selecting 'all members'. https://thalia.nu/members/

Suggested implementation

When selecting 'all members', it should be sorted Alphabetically immediately.