Allow submitters to delete their own submissions

[jmgasper]

We have added back in the ability for designers to delete their submissions (topcoder-platform/community-app#6602)

This functionality is in the community app now, but isn't currently working because the DELETE to https://api.topcoder-dev.com/v5/submissions/{submission ID} is returning a message like:

403
{
    "message": "You are not allowed to perform this action!"
}

We should allow submitters to delete their own submissions.

Validation

• After this fix, the dev community app should allow members to delete their own submissions
• Attempting to delete a submission that's not owned by a member should still fail

Test

Please ensure there is test coverage added of the cases above.