Add ability to include custom tags in InSpec

[rlakey]

Currently we cannot add additional metadata to the InSpec code that is generated.

Proposing either adding an option to include component "Addtional Questions" as additional tags or add a new option to specify new key,value custom tag data to add to controls in a component.

Currently we have these tags that are auto generated:

tag severity: 'low' tag gtitle: 'SRG-APP-000141-AS-000095' tag gid: nil tag rid: nil tag stig_id: 'VABC-50-000142' tag cci: ['CCI-000381'] tag nist: ['CM-7 a']

Custom tags would be the same so if we had an additional question of "Color" with a value of "Blue" we could check a box to indicate it should be added as a tag.

tag color: 'Blue'