This merges `osd` API into `machined`. API was copied from `osd` into `machined`, and `osd` API was deprecated. For backwards compatibility, `machined` still implements `osd` API, so older Talos API clients can still talk to the node without changes. Docs were updated. No functional changes. Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>