Add Search/Filter Functionality to API Provider Selection in Settings

[GOODBOY008]

What specific problem does this solve?

Currently, when selecting an API provider in the settings, users must scroll through a long list to find their desired provider. This is inefficient, especially as the number of supported providers grows. Users may have difficulty quickly locating the provider they want, leading to a slower and less user-friendly experience.

Who is affected and how?

All users configuring API providers in Roo Code are affected. The lack of a search/filter function slows down workflow and can cause frustration, particularly for users who frequently switch providers or are new to the available options.

When and how does the problem occur?

Whenever a user opens the provider selection dropdown in the settings, they must manually scan the list for their provider. This is especially cumbersome on smaller screens or for users with accessibility needs.

Additional context

A search/filter feature in the provider selection UI would allow users to quickly find and select their desired provider, improving usability and efficiency.

[GOODBOY008]

@mrubens PR is ready. #5278. PTAL~