Adding R/D handles for TruthQGDecorationTool, fixing bug in TruthIsolationTool
This MR provides read and decor handles to the TruthQGDecorationTool, a pre-requisite for running DAOD building in AthenaMT. It also fixes a bug in TruthIsolationTool introduced in !61926 (merged) where the name of the parent container was missed for the decor handles, leading to the decorations being orphaned.