Some clients need this to correctly interpret multipart messages.

So that we can see overall usage.

And move OSD API into separate package PVE::API2::CephOSD

To make it more usable on Andriod with Opaque.

There is enough space in the toolbar, so this is good enought for now.
Also remove some dead code, and re-ordered HDEdit to use both columns, which
looks better inside the CreateWizard.