Add "facts" properties to ASA and AireOS

[jmcgill298]

Both AireOS and ASA device classes need to implement properties that were previously associated with facts:

ASA:

• vendor
• uptime
• uptime_string
• hostname
• fqdn
• interfaces
• vlans
• model
• serial_number
• os_version

AIREOS:

• vendor
• uptime
• uptime_string
• hostname
• fqdn
• interfaces
• vlans
• model
• serial_number
• os_version