[FIX] Accordion content loss issue

Change-Id: I5ca8e320fdaf4ea9f54d44c2deb23e5de52c11b0
CSS: 0120031469 0000720876 2014
[INTERNAL] sap.m.ComboBoxBase: clear the filter when F4 or Alt + DOWN
keys are pressed

- QUnit-tests added

Change-Id: I49f99dede997443fd46e6c29f086b835040558ed
Merge "[INTERNAL] sap.m.ComboBoxBase: clear the filter when F4 or Alt + DOWN keys are pressed"
HCB implementation for FacetFilter.

Change-Id: I634d29000245aaf001250d9d8290e77dffad0417
Merge "HCB implementation for FacetFilter."
Merge "[FIX] Accordion content loss issue"