Ensure the correct name is retrieved for the coreMuon correction
The name of the coreMuon correction is created in IsolationBuilder the same way as the coreCone, so it is etconecoreMuonEnergyCorrection and not coreMuonEnergyCorrection as the accessor method currently returns. The accessor method here is updated to reflect that. This should resolve one of the issues in ATLASRECTS-5334.