Access raw file content from HTTP

[aymanbagabas]

Is your feature request related to a problem? Please describe.
Add the ability to view file contents using HTTP similar to the ssh soft repo blob ... command

Describe the solution you'd like
New endpoint /<repo>/blob/<rev>/<path> that takes the revision (branch, tag, commit) and path and returns the contents of the file. Accept both content types text/plain & application/octet-stream to return plain text or download the file at path.

#455