write e2e tests to cover entry delete use cases

[danielblagy]

Case: User tries to delete other user's entry.
Expected Result: Not Found.

Case: User tries to delete entry that doesn't exist.
Expected Result: Not Found.

Case: User tries to delete user's existing entry.
Expected Result: Success.
Note: Check if entry exists after the delete operation (should be Not Found).

[danielblagy]

BLOCKED BY #56