Reworked devices and sites - added new attribute to manage local connection to IAS

• Made si- and lt- networks optional
• Added a new attr to manage when you need lt-
• si- is probably gonna. die
• moved ts_address from device to site.

requested review from @karel.vanklink

assigned to @simone.spinelli

added 2 commits

• 98299b68 - Modify creation of site and device
• ae49b5fd - Add all the various conditions for terminating devices

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added 1 commit

• e0835db9 - Introducing is_ias_connected attribute and manage it in create_device

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added 1 commit

• 0fdd4922 - Making Vale happy

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resolved all threads

merged