Add an address argument to tfdiags.InConfigBody, and store the address
string the diagnostics details. Since nearly every place where we want
to annotate the diagnostics with the config context we also have some
sort of address, we can use the same call to insert them both into the
diagnostic.
Perhaps we should rename InConfigBody and ElaborateFromConfigBody to
reflect the additional address parameter, but for now we can verify this
is a pattern that suits us.