Feature request: Add number ranges

[gj0nyg]

In the same way that the IPAM handles networks, and then individual IP addresses underneath, it would be good if this could record direct in-dial ranges to a site, and then map individual numbers underneath. That way we could create a block of 100 contiguous numbers and then assign each number as needed and be able to see which numbers in a range are still available to be assigned.

[goteamkor]

this would be an amazing feature