Merge branch '4713-exempt-coop' into 'dev_cooperatic'

retrieve exemptions shift id and create button to register to it

See merge request !227
2 jobs from dev_cooperatic in 1 minute 29 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #4693
lint:js

00:22

passed #4694
unit:django

01:07