Upload workspace files in SSBC

[Piszmog]

With workspace files being displayed (#31791), uploading files is the last "piece" before getting parity with src.

Functionality

• During the creation/editing of the batch spec, workspace files need to be able to be upload
  • If a batch spec that has already been ran is edited, do these files get "copied" in DB or reassigned to new spec?
  • Should uploads be "flat" or can directories be uploaded/created?
• Display what files have been uploaded

Nice to haves

• Autocomplete for uploaded files

Done

• Be able to upload files
• Display uploaded files
• Run the batch change as if src batch remote was ran

[courier-new]

Depending on design capacity, maybe P1/P0?

[eseliger]

Since design capacity is going to be pretty limited, maybe we can do a 1h collaborative session on this and come up with rough wireframes that we can agree on are good enough for now and then kick eng work off?