Add PMP name colors - #1462

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### Description

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relevant motivation and context. List any dependencies that are required
for this change. -->

Replying to a PMP now displays the PMP's name instead of the underlying
displayname.
<img width="256" height="151" alt="image"
src="proxy.php?url=https%3A%2F%2Fgithub.com%2FSableClient%2FSable%2Fpull%2F%3Ca+href%3D"https://github.com/user-attachments/assets/b82be835-bcfe-4797-9387-783af50dfef2">https://github.com/user-attachments/assets/b82be835-bcfe-4797-9387-783af50dfef2"
/>

Part of SableClient#1279

#### Considerations

- The reply does not indicate that the message author is a PMP. This
could be used for impersonation. However, it's unlikely that someone
would not notice that the message is not coming from a PMP, given that
it is indicated on the actual message.
- Currently does not implement SableClient#1462, once one of these two PRs is
merged the other will have to add a fix. (Stacked PRs pls
:pleading_face:)

#### Type of change

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

### Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings

### AI disclosure:

- [ ] Partially AI assisted (clarify which code was AI assisted and
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- [ ] Fully AI generated (explain what all the generated code does in
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