feat: add upload folder command and improvs

[lordshashank]

• Implements uploadFolder CLI command, which recursively uploads all the files in folders to pdpservice.
• Implements optional parameter of valid-time for jwt creation and defaults it to 24 hours.
• Implements option addRoots parameter to uploadFile and uploadFolder command to upload and add root of particular file/folder in one go rather than running separate commands.
• Refactors code to use functions for repetitive tasks.

Future improvs:-

• multiple root additions in single POST call to pdp-miner has some bugs i.e. is not working properly, hence currently makes multiple request for each roots.