Read networks from file in different formats

[israel-lugo]

We've had user requests to be able to read networks from various formats. Popular IPAM tools, CSV, SQL, and so on.

Not quite sure how we'd do on the interface side... Especially with regards to SQL, we need to have some way for the user to define the schema for us to retrieve it. But this needs addressing. CSV is probably the easiest to start with.

[israel-lugo]

What kind of fields are we hoping to read from CSV, here? We only really care about IP addresses.

We could deal with this generically, by having each format have its own options, where the user can specify the schema. Basically, what we need is to know "get the IP addresses from field X".

For now, we can create a generic "read anything that looks like an IP" format.