COE-852: Two Line asset hierarchy are created

[namnhatpham]

Create SITE then Update it instead of combining both steps when creating

[mvoigt-sag]

@namnhatpham can you please test if the following scenario also works:

• the "Simulator SITE" exists
• the "Simulator LINE" does not exist
• after restarting the oee-simulators, the line and the site both exist once and are assigned correctly; the devices are assigned to the line

[namnhatpham]

@namnhatpham can you please test if the following scenario also works:

• the "Simulator SITE" exists
• the "Simulator LINE" does not exist
• after restarting the oee-simulators, the line and the site both exist once and are assigned correctly; the devices are assigned to the line

I intend to make another branch to give fix to hierarchy issue that I have realized during the work with this branch