Sample example for relay command.

[vbothe23]

IMPORTANT: All PRs must be linked to an issue (except for extremely trivial and straightforward changes).

Fixes #233

Description
This PR contains sample for the relay feature. This sample utilizes following modules.

• RtspClientSrc
• Mp4ReaderSource
• H264Decoder
• ColorConversion
• ImageViewerModule

Sample: Switch the stream from live to recorded and vice versa.

• The pipeline reads the h264 encoded frames from RtspClientSrc and MP4ReaderSource for live and recorded streams.
• The H264 frame will be transformed to YUV420 formatted frame through H264 decoder.
• Transforming YUV420 frame to RAW RGB format using ColorConversion.
• Rendering RAM RGB frames on the ImageViewerModule.

To run the pipeline -

• Provide RTSP camera URL from the command line. By default the live stream will start rendering.
• Enter r to switch to the recorded stream.
• Enter l to switch back to the live stream.
• Enter s to stop the pipeline.

Alternative(s) considered

Have you considered any alternatives? And if so, why have you chosen the approach in this PR?
No

Type
Other

Screenshots (if applicable)

Checklist

• I have read the Contribution Guidelines
• I have written Unit Tests
• I have discussed my proposed solution with code owners in the linked issue(s) and we have agreed upon the general approach

[mraduldubey]

please merge changes here, test and push in same PR: https://github.com/AdityaKBhadragond14/ApraPipes/tree/ab/timelapse_sample