Add consistency checks to template files

[poveden]

Summary

Currently the tool will blindly merge the files without checking if parameters or variables are being declared or consumed within the individual templates or the final merged template. Although the merged file may be consistent, individual template files should be standalone.

Desired solution

• Warn when parameters or variables
  • are being declared but not used
  • are being used but not declared
• Check both individual template files and the merged file

Additional Context

The Azure Resource Manager (ARM) Tools Visual Studio Code plugin does a pretty good job at highlighting these issues.