[Health] Ensure BGP ASN is using approved IANA ranges

[arudell]

Add checks for Muxes and Gateways to validate the BGP AS number that is defined. Ensure that it falls within the private range 64512-65534

https://www.iana.org/assignments/as-numbers/as-numbers.xhtml

While NC will accept the configuration, it typically gets blocked and not easily identified why resource configurationState is 'Failed' or 'InProgress'