Add custom icon for Anthropic hosted models (#16436)

This commit adds a custom icon for Anthropic hosted models.


![CleanShot 2024-08-18 at 15 40
38@2x](https://github.com/user-attachments/assets/d467ccab-9628-4258-89fc-782e0d4a48d4)
![CleanShot 2024-08-18 at 15 40
34@2x](https://github.com/user-attachments/assets/7efaff9c-6a58-47ba-87ea-e0fe0586fedc)


- Adding a new SVG icon for Anthropic hosted models.
  - The new icon is located at: `assets/icons/ai_anthropic_hosted.svg`
- Updating the LanguageModel trait to include an optional icon method
- Implementing the icon method for CloudModel to return the custom icon
for Anthropic hosted models
- Updating the UI components to use the model-specific icon when
available
- Adding a new IconName variant for the Anthropic hosted icon

We should change the non-hosted icon in some small way to distinguish it
from the hosted version. I duplicated the path for now so we can
hopefully add it for the next release.

Release Notes:

- N/A

assets/icons/ai_anthropic_hosted.svg

@@ -0,0 +1,11 @@
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+<g clip-path="url(#clip0_1896_18)">
+<path d="M11.094 3.09999H8.952L12.858 12.9H15L11.094 3.09999Z" fill="#1F1F1E"/>
+<path d="M4.906 3.09999L1 12.9H3.184L3.98284 10.842H8.06915L8.868 12.9H11.052L7.146 3.09999H4.906ZM4.68928 9.02199L6.026 5.57799L7.3627 9.02199H4.68928Z" fill="#1F1F1E"/>
+</g>
+<defs>
+<clipPath id="clip0_1896_18">
+<rect width="14" height="9.8" fill="white" transform="translate(1 3.09999)"/>
+</clipPath>
+</defs>
+</svg>