non-templated base class for seeding tools, added useML check to Gbts2Acts tool, EFTRACK-142

removed unneeded templating of GBTS classes, using spacepoint indices instead of pointers, added check if useML is true to Gbts2Acts seeding tool, EFTRACK-142

Trigger/TrigTools/TrigInDetPattRecoTools/src/components/TrigInDetTrackSeedingTools_entries.cxx

 #include "../TrigInDetTrackSeedingTool.h"
 #include "../Gbts2ActsSeedingTool.h"
 DECLARE_COMPONENT( TrigInDetTrackSeedingTool )
-DECLARE_COMPONENT( Gbts2ActsSeedingTool )
\ No newline at end of file
+DECLARE_COMPONENT( Gbts2ActsSeedingTool )