Enable resources to participate in progress reporting during config execution

[SteveL-MSFT]

Summary of the new feature / enhancement

As resources get executed, need progress returned as JSON for agents to display. Consider how child processes can participate including resources.

Proposed technical implementation details (optional)

No response

[anmenaga]

The mechanism for reporting progress will be similar to verbose messages - #89
In human-readable mode - just a text in stdout.
In machine-readable mode - a JSON structure returned in the stderr stream that has a string operation name and an integer [0;100] that shows completion percent; the same interface will be used to report progress from resources/resource providers to dsc.exe

[anmenaga]

To put more context to this.
The main work item to enable progress reporting (as well as streaming results from a resource in real-time without waiting until it completes the operation) is actually to switch resource execution from synchronous to async.
I did initial implementation of it using tokio runtime.