Create function for comparing FFE node labels

[chrismarget-j]

The FFE feature in apstra versions node labels by appending / incrementing a node label suffix of the form _vNN where _v are literal characters 0x5F and 0x76. and NN is a variable length string of digits (0x30 - 0x39).

The suffix is guaranteed to be at least 3 characters long (first FFE suffix will be _v2 -- _v0 and _v1 will never appear as an FFE-generated suffix) and has no defined upper length bound.

The entire label will never be more than 64 characters.

Each time a new label is required the label is trimmed so that label+suffix doesn't exceed 64 characters.

The code responsible is the _gen_label function in aos/reference_design/fabric_expansion_util.py.

Our terraform provider has a check which attempts to discern whether a given label is the suffixed-version of an un-suffixed label:

Is foo_v2 a revision of foo?

It's at the end of Read() in apstra/resource_datacenter_device_allocation.go:
https://github.com/Juniper/terraform-provider-apstra/blob/69d2449cbaf51b54377a581b06fa938f5e94c603/apstra/resource_datacenter_device_allocation.go#LL173C1-L185C1

This check will fail with labels which have been trimmed to apply the suffix.

We need a function which compares labels with the trim mechanism in mind.

That function should be tested with un-suffixed labels which end _v2.