[UI Enhancement] Organization Dropdown Lacks Search Functionality

Description:

Currently, the organization dropdown in the course creation form displays a long list of organizations without a search or filtering option, as in the zoomed-out image below. As a result, users must manually scroll through the entire list to find the desired organization, which becomes increasingly inconvenient when dealing with a large number of organizations.

I found this behavior when testing this PR: https://github.com/openedx/frontend-app-authoring/pull/1689

How to reproduce:

• ENABLE_CREATOR_GROUP should be true and settings.ORGANIZATIONS_AUTOCREATE should be set to False
• Go to Studio > Home Page (Where courses are listed)
• Click on Create New Course button
• You can see the Organization input with 'No Option' written
• Observe the long list and the lack of a search/filter feature.
• Try to find a specific organization, requiring extensive scrolling.

Additional Context

A zoomed-out screenshot is attached, highlighting the scrolling issue. Adding search functionality will significantly enhance the user experience.

Start at the Studio Home Page's Create New Course form and inspect the organization input exercised by PR #1689, using ENABLE_CREATOR_GROUP=true and settings.ORGANIZATIONS_AUTOCREATE=false. Confirm the current long-list behavior, then define done as allowing users to search or filter organizations so a specific organization can be found without extensive scrolling.