T7374: allow use of exisiting vyconf replacements for my_* commands

[jestabro]

Change Summary

This requires merge of PRs:
vyos/vyconf#23
vyos-legacy/libvyosconfig#40
vyos/vyos-1x#4526

Conditionally call vy_* replacements for certain my_* commands, notably my_set and my_commit.

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/vyconf#23
vyos-legacy/libvyosconfig#40
vyos/vyos-1x#4526

Component(s) name

Proposed changes

How to test

Smoketest result

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

[github-actions]

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No issues in PR Title / Commit Title

[sarthurdev]

Simple change for when vyconf backend is active

[dmbaturin]

Since everything falls back to the old backend unless VyConf is explicitly enabled, I see no reason not to merge this into current. We should give people a way to test the new backend without having to install it by hand.