Add nightly CI workflow for slow-tagged Beauti tests

[walterxie]

Add nightly CI workflow for slow-tagged Beauti tests

[walterxie]

it seemed the github action worked differently to Mac OS. The tests are working in my local but they cannot simulate the "click" event properly in github.

[ERROR] BeautiDivergenceDatingTest.DivergenceDatingTutorialWithEmpiricalFreqs:539->BeautiBase.clickOnNodesWithID:614->FxRobot.clickOn:59->FxRobot.clickOn:615->FxRobot.clickOn:582 » Runtime org.testfx.service.locator.BoundsLocatorException: bounds are not visible in Scene