Thaliapp: members api

Short description

Implement api for users to use in the ThaliApp

Steps to use this feature

Feature one

1. Go to api/members
2. See list of all active member's display names and photo url's

Feature two

1. Go to api/members/me
2. See dipslay name and base64 encoded photo of currently logged in user

Feature three

1. Go to api/members/<pk>
2. See dipslay name and base64 encoded photo of member with primary key