GCcollab test instance up at: https://gccollab-dev-pr-2710.azurewebsites.net/
GCconnex test instance up at: https://gcconnex-dev-pr-2710.azurewebsites.net/

Not sure if we want to also get rid of the "offer" and "remove" buttons for when there are people who applied, those buttons are added in https://github.com/gctools-outilsgc/gcconnex/blob/master/mod/missions/views/default/page/elements/related-candidates.php
They won't work in the full read only mode, but only the one who created the opportunity will see them if there are applicants and I'm not sure how often people use the apply option on the site VS. just emailing the person who posted it.

@Phanoix will wait for your thumbs up on this comment and merge the decommission of 'offer' and 'removal' with other components of CM being decommissioned. Test instance screenshots just for reference on my local side for CM in NOT in read-only mode vs CM in read-only mode:

Is completely removing the list of applicants how we want to go about it instead of just removing the buttons? Seems to me like it's removing information that some people might look for but if this is what we're going with then this does do it.