Use manual Debug impl for ChannelId to show it as a string instead of a number

[romac]

This reverts the formatting change introduced in b44ade9f8.

Before

channel_id: Some(
    ChannelId(
        2,
     ),
),

After

channel_id: Some(
    ChannelId(
        "channel-2",
    ),
),

---

PR author checklist:

• Added changelog entry, using unclog.
• Added tests: integration (for Hermes) or unit/mock tests (for modules).
• Linked to GitHub issue.
• Updated code comments and documentation (e.g., docs/).

Reviewer checklist:

• Reviewed Files changed in the GitHub PR explorer.
• Manually tested (in case integration/unit/mock tests are absent).

[hu55a1n1]

👌