grade: Resets the filter upon execution

[nus-se-script]

After grading an assignment, the find filter is reset.

Steps to reproduce (starting from a fresh install):

1. Create an assignment: add_assignment si/1 an/Test Assignment ms/100
2. Filter the first person: find Alex
3. Delete the assignment: grade si/1 ai/1 s/100
4. Note that the find filter is reset

After step 2:

After step 3 (Actual):

After step 3 (Expected): Note that the command output should be the same as the screenshot above. Other than that, the screenshot below is accurate.

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_{[original: nus-cs2103-AY2425S1/pe-interim#700] [original labels: severity.Medium type.FunctionalityBug]}

[emmannyyy]

Team's Response

This was intentional behaviour.

After the teacher does a "find" command, we believe the teacher would have already located the specific student they are looking for, and grade them. After executing the next command, it would be more appropriate for the application to revert to listing all the students in the app.

In addition, our UG did not specify that the find filter will persist after other commands are performed.

However, future iterations can improve on this, and provide users the optionality to remain in the find filter.

Severity was revised down to low, since this is a minor inconvenience that occurs in rare situations.

Duplicate status (if any):

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