chimera: compact hadles passed to NFS server

The chimera IDs on the wire presented as:

0:TAG:0000DA875B38D9E0461F9ADFEA7C7422A956:OSMTemplate

This change introduses a binary form with backward compatibility,
e.q. new version can understand and decode old forms.

The new form:

<byte 1> : fsid
<byte 2> : inode type
<byte 3> : len of the id
<byte 4:id len> id of the file
<byte ~22> : len of inode specific data
<byte 24:opque len> specific data.

For example above, ithe old encoding: will produce 68 byte nfs file handle,
with new scheme - 47.

Ticket: #7927
Acked-by: Paul Millar
Target: master
Require-book: no
Require-notes: no
(cherry picked from commit 6aa5a402b63af49e12c280a9bc264b6a44c1d434)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge pull request #305 from kofemann/compact-chimera-id-2.6

chimera: compact hadles passed to NFS server