DOVER, Del. — Attorneys in the Boy Scouts of America bankruptcy case have reached a tentative settlement under which one of the organization’s largest insurers would contribute $800 million into a fund for victims of child sexual abuse.The agreement announced Monday calls for Century Indemnity Co. and affiliated companies to contribute $800 million into the fund in return for being released from further liability for abuse claims. The payment would bring the amount of money in the proposed trust to more than $2.6 billion …