fix: show error message if connection closed VSCODE-770

[tculig]

Ticket: https://jira.mongodb.org/browse/VSCODE-770

Description

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added
• I have signed the MongoDB Contributor License Agreement (https://www.mongodb.com/legal/contributor-agreement)

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Open Questions

Dependents

Types of changes

• Backport Needed
• Patch (non-breaking change which fixes an issue)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to change)

[Copilot]

Pull request overview

Fixes the data browser webview behavior when the underlying MongoDB connection is no longer active (e.g., disconnected or switched), ensuring a clear error is surfaced instead of attempting operations on a stale connection.

Changes:

• Track the active connection id per opened data-browsing webview panel and validate it on incoming webview messages.
• Return appropriate webview error messages (documents / totalCount) or VS Code modal errors (mutations) when the panel’s connection no longer matches the active connection.
• Add a dedicated test suite covering connection-mismatch behavior (VSCODE-770).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
src/views/dataBrowsingController.ts	Stores per-panel connection id and rejects data-related webview commands when the active connection has changed/closed.
src/test/suite/views/dataBrowsingController.test.ts	Adds tests validating the new connection-mismatch handling paths.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

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