Support disambiguation of identical yang identifiers in autocli

[pheller]

As implemented, it is possible (though likely incredibly infrequent) that two or more yang modules may be loaded that define elements with ambiguous identifiers in the absence of namespaces.

For example, suppose:

a.yang:

module a {
  yang-version "1";
  namespace "http://foo/bar/a";
  prefix "a";

  container baz {
    description "configure the baz component in the a namespace"
    ...
  } 
}

b.yang:

module b {
  yang-version "1";
  namespace "http://foo/bar/b";
  prefix "b";

  container baz {
    description "configure the baz component in the b namespace"
    ...
  } 
}

With netconf, it is no problem to supply a configuration for these identifiers:

<config>
  <baz xmlns="http://foo/bar/a">
    ...
  </baz>
  <baz xmlns="http://foo/bar/b">
    ...
  </baz>
</config>

However, with the CLI, it is not presently possible to differentiate between the identifiers.

Ideally, when such a condition exists, the CLI would allow configuring the ambiguous identifiers by using their yang-specified namespace prefixes, and command completion would enumerate them as well.

e.g.,:

clixon> set ?
  a:baz                 configure the baz component in the a namespace
  b:baz                 configure the baz component in the b namespace
clixon> set a:baz ...
clixon> show configuration
a:baz {
  ...
}
clixon>

[pheller]

Somewhat related, the working path shown as a result of %W in a clispec could probably omit the yang prefix unless it's ambiguous, but I can open a separate enhancement request for that if preferred.