Aside from the two special meta-arguments "connection" and "provisioner"
this is just our standard mapping from schema to conversion rules, using
the provisioner's configuration schema.
This is a temporary implementation of these rules just so that these can
be passed through verbatim (rather than generating an error) while we
do testing of other features.
A subsequent commit will finish these with their own custom rulesets.
The old parser was forgiving in allowing the use of block syntax where a
map attribute was expected, but the new parser is not (in order to allow
for dynamic map keys, for expressions, etc) and so the upgrade tool must
fix these to use attribute syntax.
This function is the main functionality of this package. So far it just
deals with detecting and renaming JSON files that are mislabeled as
native syntax files. Other functionality will follow in later commits.