Fix incorrect suggestions for state variables

[Daniel-Cortez]

What this PR does / why we need it:

Fixes incorrect suggestions for state variables used out of state scope.

Example (from #405):

new var <state_a>;

main()
{
	var = 5;
}

Error message before the fix:

test.pwn(5) : error 017: undefined symbol "var"; did you mean "var"?

After:

test.pwn(5) : error 017: undefined symbol "var"; state variable out of scope

Which issue(s) this PR fixes:

Fixes #405

What kind of pull this is:

• A Bug Fix
• A New Feature
• Some repository meta (documentation, etc)
• Other

Additional Documentation: