Use native method to recover scene position after interruption

[bnjm]

ARKit 1.5 introduces sessionShouldAttemptRelocalization which (if I understand correctly) attempts to find the real world position after a session pause / interruption. This would be a super helpful feature to have.

Docs here: https://developer.apple.com/documentation/arkit/arsessionobserver/2941046-sessionshouldattemptrelocalizati?language=objc