Duplicate bundle labels are indistinguishable on the content language settings form

Problem/Motivation

On Configuration → Regional and language → Content language and translation (`/admin/config/regional/content-language`), each bundle is listed using only its human-readable label (`$bundle_info['label']`), not its machine name. Bundle labels are not required to be unique.

When two or more bundles of the same entity type share the same label, they appear as duplicate rows in the table and administrators cannot tell which bundle they are configuring. This affects any bundleable content entity (nodes, paragraphs, media, etc.), not only Paragraphs.

Example:
- Paragraph type `text` — label: "Text"
- Paragraph type `sidebar_text` — label: "Text"

Both appear as "Text" in the Paragraph row. Changing `sidebar_text`’s label to "Sidebar text" makes it visible again, which confirms the bundles are present but indistinguishable by label alone.

Steps to reproduce

1. Ensure the Language module and Content translation are enabled.
2. Create two bundles of the same entity type with the same label, e.g.:
- Paragraph type `text` — label "Text"
- Paragraph type `sidebar_text` — label "Text"
3. Go to `/admin/config/regional/content-language`.
4. Enable custom language settings for Paragraph (if not already).
5. Open the Paragraph details section.

Expected: Each bundle is listed and clearly identifiable (e.g. label + machine name, or unique display per row).
Actual: Only one paragraph labeled 'text' is visible/listed.

Proposed resolution

When multiple bundles of the same entity type share the same label string, append the bundle machine name for display only, e.g.:
- `Text (text)`
- `Text (sidebar_text)`
Unique labels should remain unchanged. Form structure and configuration export must continue to use bundle machine names only.

User interface changes

Duplicate bundle labels on the content language settings form show the machine name in parentheses.