Massachusetts has begun awarding grants to local agencies to set up temporary housing sites for homeless families. The state is scrambling to newly arriving migrants places to stay after hitting a state-imposed limit of 7,500 families in the state’s emergency homeless shelter system. Catholic Charities Boston is the first organization to be awarded a grant to provide temporary rooms to extremely low-income families with children and pregnant individuals. The grant will fund a site in greater Boston that opened Tuesday and can accommodate up to 27 families, or about 81 people, as they wait to enter the state’s emergency shelter system