This fix tries to address the issue raised in discussion of
PR 28735 where it was not possible to manage plugin based on
plugin ID. Previously it was not possible to invoke
`docker plugin inspect` with a plugin ID (or ID prefix).
This fix updates the implementation of `docker plugin inspect`
so that it is possbile to search based on a plugin name, or a
plugin ID. A short format of plugin ID (prefix) is also possible,
as long as there is no ambiguity.
Previously the check of `docker plugin inspect` was mostly done
on the client side. This could potentially cause inconsistency
between API and CMD. This fix move all the checks to daemon side
so that API and CMD will be consistent.
An integration test has been added to cover the changes.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>