Update reference docs (conceptual and API usage) to match latest APIs

[dixonjoel]

What does this Pull Request accomplish?

Updates the reference documentation to match the latest in the Python APIs

Why should this Pull Request be merged?

Accurate documentation. Also, there's a desire to have conceptual documentation for the Measurement Data Services ecosystem, so this could be a starting point for that.

What testing has been done?

Docs

[Copilot]

Pull request overview

This PR updates the reference documentation to align with the latest Python API changes in the Measurement Data Services ecosystem. The updates modernize the API interface by moving types to public modules, simplifying parameter names, and clarifying enum values.

Changes:

• Updated import statements to use public API modules instead of internal _types modules
• Renamed API parameters for consistency (extensions → extension, measurement_name → name, field-specific names consolidated to name)
• Simplified method signatures (e.g., create_alias now takes positional parameters instead of keyword arguments)
• Updated enum values to remove redundant prefixes (e.g., Outcome.OUTCOME_PASSED → Outcome.PASSED)
• Renamed field identifiers for clarity (data_type → value_type, type → step_type/condition_type)
• Enhanced data type documentation with more specific type names

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
docs/reference/using-measurement-data-services.md	Updated all code examples to use the latest API signatures, including imports, parameter names, enum values, and query syntax
docs/reference/ni-metadata-store.md	Updated field documentation to reflect renamed parameters (extension, name fields) and improved structure with "Core Entities" section
docs/reference/ni-data-store.md	Updated field documentation and data type descriptions to match current API, clarified enum values and type nomenclature

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[dixonjoel]

@csjall I'm curious if you've read these in detail whether you think it would be at least a good starting point for language-agnostic conceptual documentation for MDS.