Add mya groups information to channel endpoint or other metadata

[apcarp]

The channel end point does not expose any of the archiver's group information nor does the metadata field in other end points. We should add this. Here is example output from the archive command (e.g., {BPM MyRestore}).

> archive -h groups

Explore Archive Groups. You may get the attributes of a named group as well
as optionally get information about the channels contained in the group. You
may also recursively show contained groups.

Usage: -g[<opt>] [-m<opt>] [-b<opt>] [-e[<opt>]] [-nopvs]
g; Group name
m; Mya deployment; default = ops
b; Brief output
e; Exclude child groups
nopvs; Don't show PV Information

Note -g : No group name supplied means all root level groups
Note -b : Use the -b argument to limit the information about an item, group
  or channel; -b0 means very brief and -b1 means brief.
Note -e : Exclude child groups. Use -e or -e0 for no child groups. A number
  greater than zero means depth of groups to include.

Examples:
  archive -g -nopvs           # The hierarchy of all groups
  archive -g -nopvs -e -b0    # The names of root level groups
  archive -g Areas -nopvs -e1 # Details of all immediate groups under 'Areas'
  archive -g BPM -e           # Channel details in the 'BPM' group

[43] 9:51:50 adamc@opsnx93 > archive -g BPM -e | head -n10
BPM (members:52561 Active owner:mya)
|.. E101B05BGMD: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}
|.. E101B05BMOD: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}
|.. E101B05BSCN: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}
|.. E101B05CRTEXP: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}
|.. E101B05SCTM.STR1: host=opsmya8, active=1, request=1, type=0, size=1 {BPM MyRestore}
|.. E201B05BGMD: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}
|.. E201B05BMOD: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}
|.. E201B05BSCN: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}
|.. E201B05CRTEXP: host=opsmya9, active=1, request=1, type=3, size=1 {BPM}