[9.18] fix: usr: Fix algoritm rollover bug when there are two keys with the same...

[9.18] fix: usr: Fix algoritm rollover bug when there are two keys with the same keytag

If there is an algorithm rollover and two keys of different algorithm share the same keytags, then there is a possibility that if we check that a key matches a specific state, we are checking against the wrong key. This has been fixed by not only checking for matching key tag but also key algorithm.

Closes #4878

Backport of MR !9381

Merge branch 'backport-4878-fix-algorithm-rollover-keytag-conflict-bug-9.18' into 'bind-9.18'

See merge request isc-projects/bind9!9394