If you set up heat with trusts enabled, heat fails to create remote
stack since by default it creates trusts with turned off redelegation.
This commit adds a new option `allow_trusts_redelegation`
(False by default) which, when enabled together with
`reauthentication_auth_method` set to `trusts` will make Heat to create
trusts with allow_redelegation=True, both for trusts used for deferred
auth and for long creating stacks.
Change-Id: I73e73455139a87fb798fd8a4651c075a91be75fd
Story: #2005062
Task: 29606
Task: 17266