NdiReceiver should expose the last-received VideoFrame information

[RichardTea]

When using a RenderTexture as the target there does not appear to be any way to find the resolution and aspect ratio of the stream.

I have to guess a suitable RenderTexture size, and it doesn't seem like there is any way to apply letterbox/pillarboxing in my rendering UVs

There's also a lot of useful information like the timecode and timestamp of the last-good-frame which appears to be unavailable.

Can NdiReceiver please store the last-good VideoFrame information?
At a minimum I'd like:

• Width (pixels)
• Height (pixels)
• Aspect Ratio
• Timecode
• Timestamp

These are all available in NdiReceiver.TryReceiveFrame(), so should be trivial to store.