pass input metadata to resource

[tgauth]

PR Summary

• extract existing schema validation logic in subcommand.rs into helper function to call from there and add_metadata()
• modify add_metadata() to:
  • insert _metadata key into properties for resources that permit it in their schema
  • extend existing metadata key for adapters
• add related pester tests

PR Context

• any input metadata for a resource should be passed to the resource invocation, if resources permit it in their schema

[Copilot]

Pull Request Overview

This PR modifies the add_metadata() function to pass input metadata from configuration resources to the actual resource invocations, enabling resources to access metadata during operations.

• Modified add_metadata() function to accept an optional resource_metadata parameter
• For adapters, extend existing metadata with input metadata
• For resources, insert metadata as _metadata key in properties

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
dsc_lib/src/configure/mod.rs	Modified add_metadata() function signature and logic to handle resource metadata, updated all call sites to pass resource metadata
dsc/tests/dsc_metadata.tests.ps1	Added comprehensive tests for metadata passing across different operations (get, set, test, export)

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[tgauth]

@SteveL-MSFT - looks like the key name is metadata for adapters, but the test resource uses _metadata. Should I standardize to one name?

[Gijsreyn]

@michaeltlombardi should this have a doc-impact label and requires to be documented for resource authors?