Terminal views all show same name 'Terminal' in Ctrl+F7 view switcher popup

## Problem

When multiple Terminal views are open and you use **Ctrl+F7** to cycle through open views, the view switcher popup shows all terminal entries with the same name **"Terminal"**. This makes it impossible to distinguish which terminal to switch to.

The Terminal tabs/views have the correct name:

## Expected Behavior

Each Terminal view should have a unique name in the popup, e.g. **"Terminal 1"**, **"Terminal 2"**, **"Terminal 3"**, matching the tab label shown in the view itself.

## Steps to Reproduce

1. Open 2 or more Terminal views (e.g. via `Window > Show View > Terminal` multiple times)
2. Press **Ctrl+F7** to open the view switcher popup
3. Observe that all terminal entries are listed as **"Terminal"** — no numbering to differentiate them

## Environment

- **View class:** `TerminalsView`
- **Contributing plug-in:** `org.eclipse.terminal.view.ui` (1.0.100.v20260410-1230)
- **View identifier:** `org.eclipse.terminal.view.ui.TerminalsView`
- Terminal Feature 1.0.100.v20260410-1244 org.eclipse.terminal.feature.feature.group Eclipse.org
- Eclipse Version: 2025-12 (4.38)

## Additional Context

The tab labels in the view stack itself correctly show numbered terminals (e.g. "Terminal 1", "Terminal 2"), but the `getPartName()` or equivalent method used for the Ctrl+F7 switcher does not reflect this numbering.

A fix would likely involve ensuring the view's `getPartName()` (or the secondary ID / content description) returns the numbered name so the switcher can display it distinctly.