Completion provider for sqf provides variable suggestions

[Ansible2]

The completion provider should be able to suggest variables that have been previously defined.

*This doesn't necessarily need to be smart in that it will check for variables available in a given scope.

[Ansible2]

Current Issues:

• things such as parenthesis are not excluded from selecting a "word".
  • for example, a word could be "(_convoyThing" or "["_convoySeperation",20,[123]]" with the current regex
• There are duplicate completion items provided if a word appears more than once in a document