Revert "Revert "util: T2226: rewrite merge config to use cmd""
Revert "Revert "util: T2226: rewrite merge config to use cmd""

This reverts commit 6086b7fa718f502563a17569abc81d4ccb94818c.

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x