OAccessibleContextHelper methods are locked by OExternalLockGuard
which effectively only locks its ExternalMutex (i.e. SolarMutex);
so ensure that all sub-classes actually pass in a SolarMutex
by removing the default constructor.
(since these classes are in comphelper they can only use the
SolarMutex indirectly)
This uncovers that AccessibleToolPanelDeckTabBarItem and
OAccessibleControlContext did not pass in SolarMutex before.
Change-Id: Ib9085eeee6225f7c74b158e72f04b1bf62622071
da21e9de6a