Using local metadata in beamtime folder

[zain-sohail]

Instead of Scicat, the idea has become to locally store the metadata. So the flash loader needs to be adapted to handle this case.

[kutnyakhov]

@zain-sohail, maybe you can check it - I just added within #534 metadata, retrieve from the local beamtime folder.
It checks for SciCat and if it is not available, then gets metadata from the beamtime.json file and also from the local meta folder using the corresponding yaml file.