Migrate Grafana tools to new tool design

[alzimmermsft]

What does this PR do?

Migrates Grafana tools to new design where Register and Bind options are based on Option attributes.

GitHub issue number?

[Link to the GitHub issue this PR addresses]

Pre-merge Checklist

• Required for All PRs
  • Read contribution guidelines
  • PR title clearly describes the change
  • Commit history is clean with descriptive messages (cleanup guide)
  • Added comprehensive tests for new/modified functionality
  • Created a changelog entry if the change falls among the following: new feature, bug fix, UI/UX update, breaking change, or updated dependencies. Follow the changelog entry guide
• For MCP tool changes:
  • One tool per PR: This PR adds or modifies only one MCP tool for faster review cycles
  • Updated servers/Azure.Mcp.Server/README.md and/or servers/Fabric.Mcp.Server/README.md documentation
  • Validate README.md changes running the script ./eng/scripts/Process-PackageReadMe.ps1. See Package README
  • For new or modified tool descriptions, ran ToolDescriptionEvaluator and obtained a score of 0.4 or more and a top 3 ranking for all related test prompts
  • For tools with new names, including new tools or renamed tools, update consolidated-tools.json
  • For renamed tools, follow the Tool Rename Checklist and tag the PR with the breaking-change label
  • For new tools associated with Azure services or publicly available tools/APIs/products, add URL to documentation in the PR description
• Extra steps for Azure MCP Server tool changes:
  • Updated command list in servers/Azure.Mcp.Server/docs/azmcp-commands.md
  • Ran ./eng/scripts/Update-AzCommandsMetadata.ps1 to update tool metadata in azmcp-commands.md (required for CI)
  • Updated test prompts in servers/Azure.Mcp.Server/docs/e2eTestPrompts.md
  • 👉 For Community (non-Microsoft team member) PRs:
    • Security review: Reviewed code for security vulnerabilities, malicious code, or suspicious activities before running tests (crypto mining, spam, data exfiltration, etc.)
    • Manual tests run: added comment /azp run mcp - pullrequest - live to run Live Test Pipeline

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[Copilot]

Pull request overview

This PR migrates the Grafana workspace listing tool to the newer attribute-based options/binding model (moving away from the old RegisterOptions/BindOptions + ParseResult approach), and updates the toolset to align with the newer SubscriptionCommand<TOptions, TResult> pattern. It also includes a small, unrelated cleanup in the Insights toolset and adds a server changelog entry.

Changes:

• Migrated WorkspaceListCommand to the new options binding flow (Option attributes + SubscriptionCommand<TOptions, TResult>) and removed direct System.CommandLine usage from the Grafana toolset.
• Updated Grafana options + tests to use the new subscription-command testing base and option model.
• Removed now-unneeded global-usings usage patterns in Grafana and Insights (replacing with per-file using where needed) and updated project references to $(RepoRoot).

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tools/Azure.Mcp.Tools.Insights/src/Services/InsightsService.cs	Adds explicit System.Text.Json import after removing global usings.
tools/Azure.Mcp.Tools.Insights/src/GlobalUsings.cs	Removes global using for System.Text.Json (file deleted).
tools/Azure.Mcp.Tools.Insights/src/Commands/InsightsGetCommand.cs	Adds explicit System.Text.Json import; removes unused extension import.
tools/Azure.Mcp.Tools.Insights/src/Azure.Mcp.Tools.Insights.csproj	Switches Core project reference to $(RepoRoot) form.
tools/Azure.Mcp.Tools.Grafana/tests/Azure.Mcp.Tools.Grafana.Tests/WorkspaceListCommandTests.cs	Updates tests to use SubscriptionCommandUnitTestsBase and new test helpers namespace.
tools/Azure.Mcp.Tools.Grafana/src/Services/Models/ManagedGrafanaData.cs	Simplifies JSON deserialization helper to use source-gen JsonTypeInfo.
tools/Azure.Mcp.Tools.Grafana/src/Options/Workspace/WorkspaceListOptions.cs	Replaces inheritance-based options with flat [Option]/[OptionContainer] POCO implementing ISubscriptionOption.
tools/Azure.Mcp.Tools.Grafana/src/GlobalUsings.cs	Removes global using for System.CommandLine (file deleted).
tools/Azure.Mcp.Tools.Grafana/src/Commands/Workspace/WorkspaceListCommand.cs	Migrates command execution signature to ExecuteAsync(context, options, ct) and new subscription command base.
tools/Azure.Mcp.Tools.Grafana/src/Azure.Mcp.Tools.Grafana.csproj	Removes direct System.CommandLine package reference; switches Core project reference to $(RepoRoot).
servers/Azure.Mcp.Server/changelog-entries/1784300177737.yaml	Adds a changelog entry (currently needs description alignment with actual changes).