Support needed for identifying members-only videos in YouTube API

**Is your feature request related to a problem? Please describe.**
The `search().list` API returns only IDs of public videos(e.g. videos/shorts/live). However, it does not return video IDs for members-only videos.

**Describe the solution you'd like**
1. Provide an exclusive API to access members-only videos or include members-only video IDs in the `search().list` API.
2. Allow API users who are members (with proper subscription) to access members-only video metadata.
3. Allow content owners to grant API keys or OAuth credentials the right to access members-only video metadata.

**Describe alternatives you've considered**
N/A

**Additional context**
I'm working on a menu search project where I use `search().list` API to get a list of video IDs, and then call `videos().list` API to retrieve details for each video.

I noticed that `search().list` only returns IDs for publicly available videos. Members-only videos are not included.

If I manually find a members-only video and call `videos().list` with its ID, I can still retrieve detailed metadata.
To avoid this manual work, I hope there can be a way to also retrieve or include IDs of members-only videos.