Enable selection of content inside brackets or string via mouse double-click

[dmitrivMS]

Fixes #9123

Enables selection of brackets/string contents by double-clicking next to bracket/quote inside.

Does not include any of the following:

• Support for interpolated or multi-line strings
• Support for comments
• Support for regex literals
• Command or key-binding for such functionality

I considered adding a setting to turn this off, but decided against it for now because double-clicking in such locations seem to do nothing particularly useful today.

[Copilot]

Pull request overview

This PR enables selection of content inside brackets or strings by double-clicking next to the opening or closing delimiter. The feature integrates into the existing double-click word selection behavior in the editor.

Key Changes:

• Added _trySelectBracketContent and _trySelectStringContent methods to ViewController to detect and select content when double-clicking adjacent to delimiters
• Modified the double-click handler in dispatchMouse to attempt bracket/string content selection before falling back to word selection
• Added helper method _select to apply selections via core commands

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
src/vs/editor/browser/view/viewController.ts	Implements the core logic for detecting double-clicks near brackets/quotes and selecting the content inside; integrates with existing mouse dispatch handling
src/vs/editor/contrib/bracketMatching/test/browser/bracketMatching.test.ts	Adds tests for bracket content selection, though the tests manually simulate the expected behavior rather than testing the actual feature implementation