[INTERNAL] sap.m.Select: move some CSS styles to sap.m.SelectList

Change-Id: I892e5acd5cbc067251fccd6f6f9ce4ffb7a521a5
CR-Id: 012003146900009042122014
(cherry picked from commit a6f643672d9add2249b4c0118dc3f1d58ae2edc1)
Merge "[INTERNAL] sap.m.Select: move some CSS styles to sap.m.SelectList" into rel-1.26