Add `ISessionMigrationHandler` (#1270) #2118

Job	Run time
build (windows-latest, Release)	11m 6s
build (macos-latest, Release)	10m 23s
build (ubuntu-latest, Release)	6m 24s
build (ubuntu-latest, Debug)	6m 53s
build (macos-latest, Debug)	11m 16s
build (windows-latest, Debug)	11m 31s
publish-coverage / publish-coverage	1m 5s
	58m 38s

Provide feedback