This change makes various minor adjustments to the rendering of plans
in the output of "terraform plan":
- Resources are identified using the standard resource address syntax,
rather than exposing the legacy internal representation used in the
module diff resource keys. This fixes#8713.
- Subjectively, having square brackets in the addresses made it look more
visually "off" when the same name but with different indices were
shown together with differing-length "symbols", so the symbols are now
all padded and right-aligned to three characters for consistent layout
across all operations.
- The -/+ action is now more visually distinct, using several different
colors to help communicate what it will do and including a more obvious
"(new resource required)" marker to help draw attention to this not
being just an update diff. This fixes#15350.
- The resources are now sorted in a manner that sorts index [10] after
index [9], rather than after index [1] as we did before. This makes it
easier to scan the list and avoids the common confusion where it seems
that there are only 10 items when in fact there are 11-20 items with
all the tens hiding further up in the list.