[Feature Request] make go installable

[lordwelch]

There are only three things stopping filestash from being easily go installable.

• The files downloaded in server/plugin/plg_handler_console/src are missing.
  1. Since they are versioned in generator.go committing them to the repo should be easy
• Mime types are missing without go generate which breaks the web ui. See [Feature Request] Use stdlib mime package #955
• server/plugin/plg_image_c downloads stb_image.h from https://github.com/nothings/stb
  1. This could also be committed to the repo but I would recommend adding the cgo build tag //go:build cgo. This would allow filestash to be installed with cgo disabled

If you are interested in these changes I can open PRs

This is all an attempt to make it easier for me to deploy using https://github.com/gokrazy/gokrazy