We should have helper methods / extensions for DataContent #6825
Description
At a minimum we should have Load and Save.
Load should read from a path and preserve the file name loaded and try to decode a mime-type from that.
Save should save to a path, with an optional filename, using Name if a directory is provided in the path.
Perhaps we could consider a filename without extension to be provided and we infer the extension from the mime-type and return the saved path.
We should also have Stream based helpers.