Update main-os to latest upstream with OS customizations

[tbragaf]

Summary

Brings main-os up to date with our main branch (synced with microsoft/vscode), while preserving all OutSystems-specific customizations.

OS customizations ported

• customIcon on CompletionItem — adds customIcon?: HTMLElement to the interface in languages.ts (the file formerly known as modes.ts)
• Custom icon rendering in suggest widget — suggestWidgetRenderer.ts (now under browser/ subfolder) now checks for customIcon before the standard kind-based icon logic, and renders the custom element inside iconContainer
• OS Azure Pipelines — build/azure-pipelines/os-monaco-core-pipeline.yml restored for the monaco-editor-core build/deploy pipeline

Commits from main-os that were NOT ported (already upstream or not needed)

Commit	Reason
92cc555 Fix microsoft#178795 (Luis Oliveira)	Already merged upstream via microsoft/vscode PR microsoft#178795
75e0085 Update version	Minor version bump, superseded by upstream versioning
5a1b499, 93376c6, 7db1a2b, 9580998, 7e87a0b, 022e0ab, b5ae100	Microsoft contributor commits, all already incorporated in upstream main

Test plan

• Verify CompletionItem.customIcon is accessible in monaco-editor consumers
• Verify suggest widget renders custom icons when customIcon is set on a completion item
• Verify pipeline YAML triggers correctly on main-os branch