File/folder permissions checks

[SteveL-MSFT]

Summary of the new feature / enhancement

Anywhere that dsc reads a file, we should check that the file and it's containing directory isn't world writable. If so, we should error and not allow as it is not trusted.

Proposed technical implementation details (optional)

No response

[anmenaga]

Probably, such strict mode should be opt-in. Otherwise users, who just want to run their configs, will be getting a lot of roadblocks.

[SteveL-MSFT]

We can have it opt-out