Use the ACL factory for secured mutex creation

Opt-in Windows port of the resolved Mutex(bool,string,out bool,MutexSecurity) constructor to MutexAcl.Create. Preserve original argument order, out destination and security object. Add System.Threading.AccessControl 6.0.0 to modeled projects using MutexAcl when absent. Skip known overlong literal/constant-allocation names, unrelated constructors, initializers, named/commented syntax, deferred contexts and unsafe conditional snapshots. No ACL selection or Framework CAS/runtime-validation/native-failure emulation. Standalone, outside version composites.