Adjust order of applications shown to Board Members

[charludo]

Motivation

It's unclear how the applications are currently sorted.

User Story

As a board member, I want to be presented with applications in a sensible manner, e.g. the oldest unseen applications first.

Proposed Solution

Sort un-voted-for applications by submission date in increasing order. Afterwards, show already-voted-for offers sorted by submission date in decreasing order.

Alternatives

Some other ordering; but I do think unseen offer applications have to always be at the top.

Additional Context

Screenshots