Description of the desired feature

HDF-EOS5 file format is an easy way to save the final time-series product into a single file. There is now near-automatic support for that after #1161. However, the following metadata is missing. It will be great to provide them from the ASF HyP3 side:

• relativeOrbit: required by HDF-EOS5
• startUTC: used to calculate the first frame number
• stopUTC: used to calculate the last frame number
• ascendingNoteTime: use to calculate the first/last frame number [updated]

Then, all hyp3 products can be saved in HDF-EOS5 format, if the user just turn on the mintpy.save.hdfEos5 option, without any manual adding of metadata (as I did in here).

Let me know what you think please. @forrestfwilliams @talogan @jhkennedy

Next, we would need to update the example ASF HyP3 dataset (to include the above metadata); and cut for a new release of mintpy.