UVE: Remove duplicate "copy URL" button from editor toolbar

[zJaaal]

Description

The UVE editor renders the same "copy page URL" popover button in two places:

1. Top editor toolbar — libs/portlets/edit-ema/portlet/src/lib/edit-ema-editor/components/dot-uve-toolbar/dot-uve-toolbar.component.html lines 19-56 (pi pi-copy icon, sits next to the bookmark star).
2. Browser URL pill — libs/portlets/edit-ema/portlet/src/lib/edit-ema-editor/edit-ema-editor.component.html lines 71-105 (pi pi-link icon, on the pill that displays the URL).

Both controls render the same $pageURLS() popover and call the same triggerCopyToast(). The pill version was added in #35417 when the browser URL pill was introduced. Since the URL itself now lives on the pill, the copy button belongs there — the toolbar copy button is redundant.

Acceptance Criteria

• Remove the copy URL button (and its <p-popover>) from the top editor toolbar (dot-uve-toolbar.component.html).
• Keep the copy button on the browser URL pill in edit-ema-editor.component.html (no change).
• Clean up imports / methods / signals in dot-uve-toolbar.component.ts that become unused after the removal (e.g. ClipboardModule, triggerCopyToast, $pageURLS, copyUrlPopoverPt).
• Update dot-uve-toolbar.component.spec.ts to drop tests covering the removed control. Do not add new tests — this is purely a deletion.
• All existing portlets-edit-ema-portlet Jest tests continue to pass.

Additional Context

UI cleanup, no functional regression. The pill copy button covers the use case end-to-end (same popover, same URLs, same toast).