rest-api: Add retrieve and list endpoints for crush_type

Signed-off-by: Gregory Meno <gmeno@redhat.com>
tests: test crush_type endpoints and test osdmap crush_type property

Signed-off-by: Gregory Meno <gmeno@redhat.com>
docs: add new version to include crush_type endpoints

Signed-off-by: Gregory Meno <gmeno@redhat.com>