feat: auto-provision volumes on all machines for global services (#243)

* feat: auto-provision volumes on all machines for global services

* fix: schedule global service volumes only on machines that need them

* fix: use union of eligible machines for volumes shared by global services

* test: restore global with missing volume fails test

* refactor: simplify volume scheduler by removing redundant check

Move isVolumeSharedBetweenGlobalAndReplicated check earlier to fail
fast, then use isVolumeForGlobalService instead of the now-redundant
isVolumeOnlyForGlobalServices function.

test/e2e/fixtures/compose-global-volume.yaml

@@ -0,0 +1,10 @@
+services:
+  test-compose-global-volume:
+    image: portainer/pause:latest
+    deploy:
+      mode: global
+    volumes:
+      - test-compose-global-volume:/data
+
+volumes:
+  test-compose-global-volume: