feat: rename templating variables

[ricardomaraschini]

Description, Motivation and Context

when templating the output of the namespace connectivity check we were referring to the 'fromCIDR' as 'fromNamespace'. it makes way more sense to refer to it as 'fromCIDR' as this is how it is provided in the input for the collector.

as this is a brand new feature it is very unlikely that anyone is using it (except for the embedded cluster that still needs to be patched accordingly).

this is how the analyser was defined before (notice the templating in the message field):

apiVersion: troubleshoot.sh/v1beta2
kind: HostPreflight
metadata:
    name: ec-cluster-preflight
spec:
    analyzers:
        - networkNamespaceConnectivity:
            collectorName: check-network-connectivity
            outcomes:
            - pass:
                message: "Communication between {{ .FromNamespace }} and {{ .ToNamespace }} is working"
            - fail:
                message: "{{ .ErrorMessage }}"

and this is how it is now:

apiVersion: troubleshoot.sh/v1beta2
kind: HostPreflight
metadata:
    name: ec-cluster-preflight
spec:
    analyzers:
        - networkNamespaceConnectivity:
            collectorName: check-network-connectivity
            outcomes:
            - pass:
                message: "Communication between {{ .FromCIDR }} and {{ .ToCIDR }} is working"
            - fail:
                message: "{{ .ErrorMessage }}"