Migrate interface loop detection configuration to MongoDB

[viniarck]

As highlighted in the original EP025:

Specification
It is desirable to support ignored loops configuration that can be changed dynamically via API. Since this feature is relatively small and wouldn't require much extra entries or states, then using topology switches' and interfaces' metadata storage would simplify the implementation and maintenance since currently adding support to a new storage with storehouse requires a significant effort development-wise. In the future, this can be migrated to another storage (collection) when an alternative is available. The following metadata would be used

Back then, MongoDB infrastructure hadn't been in place yet to we made this trade-off to ship this feature, but now the configuration part (ignored_loops) that is used can be migrated to MongoDB eventually with a new API endpoint. This would imply also adapting this e2e test case too https://github.com/amlight/kytos-end-to-end-tests/blob/master/tests/test_e2e_32_of_lldp.py#L78.

I'll tag this a future_release

[viniarck]

Before prioritizing this in the future, it's worth reassessing the approach how NApps are using the settings and maybe provide a generic solutions providing a default settings storage too simplifying this and future similar implemenations that other NApps will need.