Forum Updates - restrictions added for non-participants

[ihsaan-ullah]

@ mention of reviewers

@Didayolo

A brief description of the purpose of the changes contained in this PR.

We have now added restrictions for users that are not logged-in and non-participants to not have access to the forum. Non participants cannot create threads/posts in the forum anymore

Screenshots

Not logged-in user view

Participant view

Non-participant view

Issues this PR resolves

• Is there a way to show text (download links) only to users registered to the competition? #1739

A checklist for hand testing

• Try to access a forum of a competition when you are not logged-in (Should see warning message)
• Try to access a forum of a competition when you are a participant of the competition. Make sure that you can Add thread/post, delete your post/thread
• Try to access a forum of a competition when you are NOT a participant (Should see warning message)

Checklist

• Code review by me
• Hand tested by me
• I'm proud of my work
• Code review by reviewer
• Hand tested by reviewer
• CircleCi tests are passing
• Ready to merge

[Didayolo]

@ihsaan-ullah

• As competition participant (or even as a competition organizer), I am able to see the thread list, but I get the yellow warning when trying to create a new topic

• When hitting a yellow warning, there is no Go back to competition button

[ihsaan-ullah]

@ihsaan-ullah

• As competition participant (or even as a competition organizer), I am able to see the thread list, but I get the yellow warning when trying to create a new topic
• When hitting a yellow warning, there is no Go back to competition button

Both problems are fixed

[Didayolo]

Added the "Go back" button for the case the user is not logged in. Should be all good now.