WIP: Fixes for the updated Powheg Wt_DR process, and removal of Wt_DR_onshellW and Wt_DS_onshellW processes
Following the discussion in AGENE-1819, I am adding the new options introduced in the updated Wt_DR process with the proper W offshelness treatment, and removing the temporary onshellW versions of the Wt_DR and Wt_DS processes.
Tagging also @grovelli