Provide backward compatibility for broken releases

There is a bug in h.0 that allows users to end up using -proposed
repositories even if they intend to be using the stable pocket.
In the process of fixing this situation so it can't (as easily)
happen again, we rationalized the URL format of the Cisco
main and supplemental repos so that a static string is no longer
appended to the main repo URL in code.  Because h.0 users could get
a hold of this change unintentionally, we need to provide code that
watches for the old-format URL string as it was specified in
data/hiera_data/vendor/cisco_coi_common.yaml and/or
data/hiera_data/enable_ha/true.yaml and munge the string to something
that actually works...otherwise h.0 installs will be almost
immediately broken going forward.  This patch does that, and also
checks for the case of users specifing FTP urls.

Partial-Bug: #1269856