Update title bar UI feature work and bug fixes

[dmitrivMS]

Ensured new UI is hidden under the setting.
Added call-to-action UI when minor or major version change is detected post-install.
Polished UX based on feedback.
Added telemetry event for new update UX.

Fixes #301226
Fixes #300941

[Copilot]

Pull request overview

This PR updates the update-indicator UX in the workbench (title bar + status bar), including new title bar modes, improved tooltip rendering, and post-install “what’s new” content.

Changes:

• Adds a new update.titleBar mode (always) and refines “detailed” visibility rules.
• Refactors UpdateTooltip into an externally-rendered, state-driven tooltip with version copy affordances and a post-install markdown section.
• Adds version-change detection + telemetry in the title bar contribution.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/vs/workbench/contrib/update/common/updateUtils.ts	Adds isMajorMinorVersionChange helper for version-change detection.
src/vs/workbench/contrib/update/browser/updateTooltip.ts	Refactors tooltip rendering; adds copy-version UI and post-install markdown fetch/render.
src/vs/workbench/contrib/update/browser/updateTitleBarEntry.ts	Reworks title bar indicator behavior/modes, tooltip lifecycle, version-change detection, telemetry.
src/vs/workbench/contrib/update/browser/updateStatusBarEntry.ts	Updates status bar contribution to drive tooltip rendering via renderState.
src/vs/workbench/contrib/update/browser/update.ts	Initializes titleBarEnabled earlier from configuration.
src/vs/workbench/contrib/update/browser/media/updateTooltip.css	Adjusts tooltip sizing; adds copy-button and markdown styling.
src/vs/workbench/contrib/update/browser/media/updateTitleBarEntry.css	Tweaks title bar entry height and underline styling.
src/vs/platform/update/electron-main/abstractUpdateService.ts	Import ordering change only.
src/vs/platform/update/common/update.config.contribution.ts	Extends configuration enum with always + updated descriptions.

Comments suppressed due to low confidence (2)

src/vs/workbench/contrib/update/browser/updateTooltip.ts:475

• The version copy button is only wired for mouse click. For keyboard accessibility, handle Enter/Space (keydown) to trigger the same action, and ensure focus behavior doesn’t propagate/close the hover unexpectedly.

		this._register(dom.addDisposableListener(copyButton, 'click', e => {
			e.preventDefault();
			e.stopPropagation();
			if (copyValue.value) {
				this.clipboardService.writeText(copyValue.value);
			}
		}));

src/vs/workbench/contrib/update/browser/updateTitleBarEntry.ts:287

• The hover dispose callback only calls onUserDismissedTooltip() when this.content is still connected. If the entry is removed (e.g. context key flips to false) while the hover is open, tooltipVisible may never be cleared. Consider always notifying dismissal from this dispose callback (and let the caller decide whether it was user-initiated) to avoid stale state.

				dispose: () => {
					if (!!this.content?.isConnected) {
						this.onUserDismissedTooltip();
					}
				}