[v9_11] fix dyndb issues; isc_errno_toresult() 4445. [cleanup] isc_errno_toresult() can now be used to call the formerly private function isc__errno2result(). [RT #43050] 4444. [bug] Fixed some issues related to dyndb: A bug caused braces to be omitted when passing configuration text from named.conf to a dyndb driver, and there was a use-after-free in the sample dyndb driver. [RT #43050] Patch for dyndb driver submitted by Petr Spacek at Red Hat. (cherry picked from commit 3390d74e33385337631b19e68760025e0ca5d6ec)