Submission history does not use correct syntax highlighting

**Describe the bug**
When opening the submission history to a submission that used some language other than Java, i.e., Python, the file is still highlighted as Java. The submission history should use the language specified by the submission.

**To Reproduce**
1. Create submission using Python
2. Open submission history
3. See that the file uses Java syntax highlighting

**Expected behavior**
Submission history syntax highlighting should be the same as the language used in the submission.

**Screenshots**


Start by reproducing the issue with a Python submission, then trace the submission history view and its syntax-highlighting language selection. Done means the history displays the submitted code using the submission's language rather than Java; verify this for Python and the existing Java case.

Written by the indexing model from the issue text.