Increase support for BLOBs and add additional VFS API.

[SirSpudlington]

• Fixed download so blob: and data: are checked to verify if the object is binary.
• Refactored upload script to only treat text as text
• Added additional VFS function readFileAsBuffer for returning buffer data from blob files.
• Updated docs

Opening non-mapped binary files would open them in notepad revealing the base64 blob instead of the raw data, which could be an issue.

[datkat21]

I will test this soon