GATINEAU,QUE.,-(CP)-A final report into missing children and unmarked graves at residential schools is calling on the federal government to create an Indigenous-led national commission with a 20-year mandate to investigate missing and disappeared Indigenous children. It’s also calling on Canada to refer itself to the International Criminal Court for investigation. Kimberly Murray, Canada’s special interlocutor on unmarked graves, released her final report Tuesday in Gatineau, Que., during a gathering with Indigenous residential school survivors and experts from across the country. More than 150,000 Indigenous children were forced to attend residential schools, the last of which closed in 1996. An estimated 6,000 children died in the schools, though experts say the actual number could be much higher. Many of their families were never informed of their deaths or told where they…