T6718: use the vyconf daemon for validation of set commands

[jestabro]

Change Summary

This PR has been updated with appropriate commit hashes in build.sh, following merge of
vyos/vyos1x-config#31
vyos/vyconf#11
and is ready for review.

It is required by the corresponding PR for vyos-1x.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Other (please describe):

Related Task(s)

Related PR(s)

vyos/vyos1x-config#31
vyos/vyconf#11

Proposed changes

How to test

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[dmbaturin]

This will certainly work, but I wonder if we should package vyconf and its tools separately at a later point.

[jestabro]

Now that we have the whole of vyconf available, I expect we will want to refactor the distinction vyconf <-> vyos1x-config as well as packaging.

[jestabro]

This will benefit from a single commit PR for vyos-1x before merging, to make for a smooth transition (as ctypes do not, as far as I know, have a notion of optional argument, we must introduce a keyword argument with default for the python wrapper reference_tree_to_json, to accommodate the change in the underlying function). The remainder of the vyos-1x PR vyos/vyos-1x#4176 will be opened after updates to the Dockerfile, etc.

[jestabro]

After this merge, the update to the Docker file to reflect new commit hash will need to be accompanied by:
vyos/vyos-1x#4226
to avoid a chicken-and-egg problem with build time generation of the reference tree.