Add tests for `qse clear` command.

[Ashrockzzz2003]

• Add tests to new file test/clear.test.js.
• It must cover all edge cases of the clear command.

[PavanCodes05]

Hey @Ashrockzzz2003, If the issue is still open, I can work on it!

[Ashrockzzz2003]

Assigned @PavanCodes05

[adithya-menon-r]

Hey @Ashrockzzz2003, I would like to solve this issue if there is no progress...