Respect the distribution manifest ordering when listing distributions

[OneBlue]

Summary of the Pull Request

PR Checklist

• Closes: Link to issue #xxx
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated if needed and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated if needed
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[Copilot]

Pull Request Overview

Adds preservation of manifest-defined distribution ordering by switching to nlohmann::ordered_json / ordered_map and introducing tests to validate ordering.

• Replaces std::map with nlohmann::ordered_map and custom from_json to retain insertion order.
• Updates JSON parsing utilities to allow using ordered_json.
• Adds tests asserting distribution listing respects manifest order.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test/windows/UnitTests.cpp	Adds test cases to verify manifest ordering of distributions.
src/windows/common/Distribution.h	Changes ModernDistributions to ordered_map and implements custom from_json to preserve order.
src/windows/common/Distribution.cpp	Uses ordered_json in manifest parsing.
src/shared/inc/JsonUtils.h	Generalizes FromJson to accept a JSON type parameter.
CMakeLists.txt	Updates nlohmann/json dependency version.