New feature: Cut videos by start/end time

[ChristopheVeber]

Background

As an contributor, I typically try to upload GoPro timelapse videos.
The segmentation of large videos is discussed in #636.
Independently, there are cases where an existing video has to be cut and uploaded (e.g. to cut out maneuvering on a parking lot).
It would be convenient to do this via the Mapillary command line tool. Also, cutting using the Mapillary toolchain can make certain that video/time/telemetry data is consistent and meets Mapillary's own expectations.

New Feature Proposal

• By default, the Mapillary command line tool should upload the specified video completely (behavior as of today).
• If an optional start_time argument is passed, then the video is uploaded from the start_time.
• If an optional end_time argument is passed, then the video is uploaded until the end_time.

[waldyrious]

I'd like this feature, too. I have several .360 videos captured with a GoPro Max which need the start or end cut out to remove irrelevant footage. I tried extracting the images from the video locally to then manually exclude the undesired snapshots prior to uploading, but the resulting images are not treated as 360º panoramas (due to #336, I believe).

This capability would be greatly appreciated.