feat(upload): added an option to start upload at first request#1

msteinmetz-steeple wants to merge 2 commits intomastersteeple-org/flutter_package_tus_client:masterfrom

add_upload_data_during_creation_optionsteeple-org/flutter_package_tus_client:add_upload_data_during_creation_optionCopy head branch name to clipboard