'Wire transfer' as third payment option for admins

One-sentence description

A third payment option 'other' only for admins

Why?

Sometimes things are not being paid in cash nor pin/debit card. It occurs that people pay via wire transfer of something is settled (? google translate says this is the word, verrekenen) with something else or just something else financially interesting happens. This happens often for benefactors (with wire transfers) but occasionally with events too (when people do not pay at the activity but upfront). For clarity it would be nice to be able to register this correctly in the Thalia website. It is especially useful to check the bookkeeping because the 'other' payments are interesting. Because only the board should do these kind of payments, this option should only be available for people with board permissions.

Current implementation

There are 2 options for payments.

Suggested implementation

A third option for payments, that can only be used by board members.