Cross-tenant sync

Example scenario

LIDL makes a purchase order to ISOMAT to transfer some goods to a LIDL store.

ISOMAT does the transportation planning. It decides that the goods will be transferred from WH1 to WH2, and then from WH2 to the LIDL store.

ISOMAT executes the WH1 -> WH2 leg and assigns the WH2 -> LIDL store leg to MYTIS.

LIDL	ISOMAT	MYTIS
Outgoing PO1: `___ -> LIDL store`, client `ISOMAT`	Incoming PO2 (PO1): `WH1 -> LIDL store`, client `LIDL`	-
-	FU1 (PO1): `WH1 -> LIDL store`	-
-	FO1 (FU1): `WH1 -> WH2`	-
-	Owned T1 (FO1): `WH1 -> WH2`	-
-	FO2 (FU1): `WH2 -> LIDL store`	-
-	External T2 (FO2): `WH2 -> LIDL store`	-
-	Outgoing PO3 (T2): `WH2 -> LIDL store`, client `MYTIS`	Incoming PO4 (PO3): `WH2 -> LIDL store`, client `ISOMAT`
-	-	FU2 (PO3): `WH2 -> LIDL store`
-	-	FO3 (FU2): `WH2 -> LIDL store`
-	-	Owned T3 (FO3): `WH2 -> LIDL store`