Fix wrong behaviour of queue on duplication

[WKBae]

The queue behavioured incorrectly on duplicate operation(as stated here), which can be reproduced with this code: 상받빠빠망망망하; the expected output is 333, but 330 is printed.

This commit fixes the issue of the code moving values when there is no space to insert at front, as following:

1. The values start from queue_front + 1, not queue_front
2. current_stack_top should be increased as the contents are pushed back.

[disjukr]

Could you please add that behavior to standard test case?