[FEATURE] Add VNAV checking to the Language Server

[itsxallwater]

Is your feature request related to a problem? Please describe.
Many shops don't catch runtime-errors like VNAVs until execution occurs and the error is logged. Some flavors, like jBASE, will warn you about runtime errors during compilation but some of these errors would be relatively easy to look for when developing in a disconnected manner with no compiler access.

Describe the solution you'd like
The language server already evaluates for things like labels that are defined but not used so I believe it can be made to look for VNAV scenarios.

Describe alternatives you've considered
The alternative here is really the current state, wherein connectivity is required to the execution environment so that at best, the code can be compiled to verify or at worst, the code has to run to observe a VNAV.

Additional context