Accessible View: include file paths for inline references in chat responses (#301565)

* Initial plan

* Add inline reference handling with file paths to Accessible View

When the Accessible View renders chat responses, inline file references
(kind: 'inlineReference') were previously skipped entirely. This adds
handling to include the file name and full path (and line number for
locations) so screen reader users get the same context as the visual UI.

- Handle URI references: show "name (path)"
- Handle Location references: show "name (path:line)"
- Handle workspace symbol references: show "name (path:line)"
- Add 3 new tests verifying inline reference rendering

Co-authored-by: meganrogge <[email protected]>

* Revert unintended monaco.d.ts changes from gulp compile

Co-authored-by: meganrogge <[email protected]>

* Rename ambiguous variable in test (location -> fileLocation)

Co-authored-by: meganrogge <[email protected]>

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Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: meganrogge <[email protected]>
Co-authored-by: Megan Rogge <[email protected]>