[Draft] Adds nested Edge hierarchy creation command

[c-ryan-k]

Raising this PR in draft mode to get initial feedback while we discuss future enhancements.

• Adds az iot edge hierarchy create experimental command that:
  • Allows users to create nested edge hierarchy configurations from inline --device arguments or with a YAML/JSON config file
  • Has switches for visualization of desired hierarchy and operation progress as well as whether or not to delete all hub devices before continuing
  • Performs the following operations on the hub:
    • (optional) Delete all existing device identities
    • Create new device identities
    • Set parents of devices according to hierarchy input
    • Set module deployments on devices as specified in input

New dependency: treelib - used as a helper for validating device hierarchies and visualization.

Unfinished tasks:

• Currently only supports creating devices with default authentication method
• Creation of 1000s of devices is possible with this command, which may significantly impact device identity registry quotas. We may want to discuss the possibility of limits / warnings for excessive amounts of devices.
• Does not process additional edge configuration content / device TOML files / hostname configs or certificates.

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[digimaun]

We should double-check the official terminology for this topic to ensure alignment...I've seen both "hierarchy" and "topology" being used.

[digimaun]

We should ensure the "1.0" Nested Edge Config is documented somewhere.

[digimaun]

Not strictly necessary for this PR, but at some point we need to converge on the new fixtures oriented test pattern for integration tests (as introduced in ADU CLI, and applied in this in-flight PR #582)

[c-ryan-k]

Moved to feature branch / PR #591