Keep using component_getImplementationEnvironment in extensions

...instead of relying on the implicit CPPU_CURRENT_LANGUAGE_BINDING_NAME
convention.  Keeping that convention an implementation detail makes it easier to
do improvements in the future.  (Theoretically, the bundled extension in mysqlc
could be considered internal code and not adapted, but just be safe.)

(cherry picked from commit fa2a7c1c95f78d20ed572091e12700fd4d852835)
Conflicts:
	desktop/test/deployment/active/active_native.cxx
	odk/examples/DevelopersGuide/Components/Addons/ProtocolHandlerAddon_cpp/component.cxx
	odk/examples/cpp/counter/counter.cxx

Change-Id: Iae41a6e072dabc2bf7c1481ba6cfed61680edf37
Reviewed-on: https://gerrit.libreoffice.org/7119
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>