Add Puppet Task/Plan intellisense in Puppet plan files

[glennsarti]

Once #24 is fixed, Editor Services should be updated to add Puppet Plan and Tasks intellisense for;

• Completion
• Hover
• Defintions
• Workspace Symbols

Bolt

• Extract bolt metadata (functions/types/classes) etc. from repo so it can be used by the language server. Don't want to vendor as it causes too many issues (e.g. circular deps). We just need the metadata

Completion Provider

• Add 'plan' keyword to completion
• Use bolt metadata for plan files

Definition Provider

• Use bolt metadata for plan files

Hover Provider

• Use bolt metadata for plan files

[glennsarti]

Been working on this. Unfortunately PES doesn't support Puppet 4 functions so this has turned into a rabbit hole.