Support autocomplete for TSP-Link node namespace

[Brad-O]

Subject of the issue

Autocomplete will not suggest anything if writing commands for a TSP-Link node, e.g. node[2].smu.source.func = node[2].smu.FUNC_DC_VOLTAGE

Your environment

• Your TSP shebang: --#!2450
• version of TSPLang: 0.5.0
• version of visual studio code:
  Version: 1.31.1 (user setup)
  Commit: 1b8e8302e405050205e69b59abb3559592bb9e60
  Date: 2019-02-12T02:20:54.427Z
  Electron: 3.1.2
  Chrome: 66.0.3359.181
  Node.js: 10.2.0
  V8: 6.6.346.32
  OS: Windows_NT x64 10.0.16299

Steps to reproduce

Use the TSP-Link node syntax to address a specific node, as referenced above.

Expected behaviour

Autocomplete should continue to work.

Actual behaviour

Autocomplete stops working.