feat: implement export filter functionality for resource exports

[Gijsreyn]

PR Summary

Adds engine-side post-filtering for export via a new exportFilter resource directive.

PR Context

Fixes #1486.

[Copilot]

Pull request overview

Implements engine-side post-filtering for dsc config export results via a new exportFilter resource directive, enabling consistent wildcard/equality filtering even for resources that don’t implement native export filtering.

Changes:

• Adds exportFilter to the configuration resource directives schema and applies it in the export pipeline after resource.export(...).
• Introduces configure::export_filter matching logic (case-insensitive * wildcard for strings; OR across filter objects, AND within each object) plus unit tests.
• Adds Pester coverage for exportFilter behavior and updates the dsctest export resource to emit a name property for filtering.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tools/dsctest/src/main.rs	Emits per-instance name values to enable filter-driven tests.
tools/dsctest/src/export.rs	Extends the test export payload schema with optional name.
lib/dsc-lib/src/dscresources/command_resource.rs	Adjusts when “export filtering not supported” is raised (only for non-empty input).
lib/dsc-lib/src/configure/mod.rs	Wires exportFilter from directives into the export pipeline.
lib/dsc-lib/src/configure/export_filter.rs	Adds the engine-side filtering implementation + Rust unit tests.
lib/dsc-lib/src/configure/config_doc.rs	Adds export_filter directive field to the config document model/schema.
lib/dsc-lib/locales/en-us.toml	Adds localized message for filter reduction logging.
dsc/tests/dsc_export.tests.ps1	Adds integration tests validating exportFilter behavior across scenarios.
dsc/src/resource_command.rs	Updates call site for the changed export helper function signature.