Submission endpoint: gradeSubmission
### Endpoint (Method)
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and what information you expect to have to give LabraCORE -->
| Params | Type | Comment |
|--------|------|---------|
| Input | Long | submissionId |
| | SubmissionPatchDTO | patch |
| Output | Long | submissionId (patched version) |
##### What does this method do?
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input to output. In many cases, this can just be a short explanation
of what you expect to come out. -->
1. Patch the submission of the given ID with the given patch, and return
issue