Add JSONC support and basic IDE settings for code style + fix output is created even though not specified

[o-l-a-v]

The main objective of this PR was to add JSONC support, so this tool can be used with EPAC policies, which can do both JSON and JSONC.

I also added some basic VSCode settings for recommended extensions (PowerShell, EditorConfig) and for code style (to make sure my settings did not overwrite the style that was already present in this project).

What is EPAC:

• https://azure.github.io/enterprise-azure-policy-as-code/
• https://github.com/Azure/enterprise-azure-policy-as-code

EPAC has some validation during build and deploy, but it does not catch all problems. Thus AzPolicyTest would be great to have as part of the validation before build and deploy. Ref:

• Convert-PolicyResourcesToDetails in parallel does not throw if it fails Azure/enterprise-azure-policy-as-code#777
• JSON schemas should be strict validatable Azure/enterprise-azure-policy-as-code#780

This PR resolves following feature requests:

• [Feature request] JSONC files #39
• [Feature request] Add basic .editorconfig so contributors follows code style #40

This PR resolved following issues:

• [Bug] Produces output file even though it's not specified #43

[DamirHelez]

lgtm

[o-l-a-v]

Fixed #43 in this PR too.

[tyconsulting]

thanks for the contribution. i've approved the PR and merged the code. I will create a new release in PSGallery in the coming days. i am adding an additional test too...