Enhancement: Add addition network CIDR builtins

[patrick-east]

Enhancement Description

We currently support some initial CIDR builtins from #897 but it would be useful to add some additional helpers for checking if two ranges overlap and if one is fully contained inside another for use in whitelist and blacklist checks.

Proposal

Add in two new methods:

net.cidr_intersects(a, b)   # checks if a and b share any addresses
net.cidr_contains(a, b)  # checks if b is contained in a, b can be an ip or cidr

We can then deprecate the net.cidr_overlap built-in and replace it with the net.cidr_contains. The reasoning behind this being that its less confusing since "overlap" kind of sounds like what the intersects call would be doing, but its really checking if the IP is inside the subnet.

Ex:

Whitelist CIDR use-case.

You could add a check to ensure some other CIDR was inside of it

net.cidr_contains("10.0.0.0/8", "10.1.2.0/24")

would evaluate to true, while something like:

net.cidr_contains("10.0.0.0/8", "1.2.3.0/24")

would evaluate to false

Blacklist or "in-use" use-case

With a blacklist CIDR like "10.1.2.0/24" you can check if some other CIDR overlaps with it:

net.cidr_intersects("10.1.2.0/25", "10.1.2.64/26")

would evaluate to true since they intersect from 10.1.2.64 through 10.1.2.127, and something like:

net.cidr_intersects("10.1.2.0/25", "10.1.2.128/25")

would evaluate to false since they don't overlap at all.