csip: Don't keep bond with invalid CSIS devices

This extends CSIP part with verification of SIRK of connecting member
and general member verification. Verification is done by registered in
SMP callback that validates SIRK with group known value.

Tag: #fetature
Bug: 278514112
Test: atest bluetooth_csis_test
Change-Id: Ibffbfeb81884a955f1a9111dd6646955c3bedd07