We now have RunningInAutomation has a general concern in views.View, so
we no longer need to specify it for each command-specific constructor
separately.
For this initial change I focused only on changing the exported interface
of the views package and let the command-specific views go on having their
own unexported fields containing a copy of the flag because it made this
change less invasive and I wasn't feeling sure yet about whether we
ought to have code within command-specific views directly access the
internals of views.View. However, maybe we'll simplify this further in
a later commit if we conclude that these copies of the flag are
burdensome.
The general version of this gets set directly inside the main package,
which might at some future point allow us to make the command package
itself unaware of this "running in automation" idea and thus reinforce
that it's intended as a presentation-only thing rather than as a
behavioral thing, but we'll save more invasive refactoring for another
day.
This commit extracts the remaining UI logic from the local backend,
and removes access to the direct CLI output. This is replaced with an
instance of a `views.Operation` interface, which codifies the current
requirements for the local backend to interact with the user.
The exception to this at present is interactivity: approving a plan
still depends on the `UIIn` field for the backend. This is out of scope
for this commit and can be revisited separately, at which time the
`UIOut` field can also be removed.
Changes in support of this:
- Some instances of direct error output have been replaced with
diagnostics, most notably in the emergency state backup handler. This
requires reformatting the error messages to allow the diagnostic
renderer to line-wrap them;
- The "in-automation" logic has moved out of the backend and into the
view implementation;
- The plan, apply, refresh, and import commands instantiate a view and
set it on the `backend.Operation` struct, as these are the only code
paths which call the `local.Operation()` method that requires it;
- The show command requires the plan rendering code which is now in the
views package, so there is a stub implementation of a `views.Show`
interface there.
Other refactoring work in support of migrating these commands to the
common views code structure will come in follow-up PRs, at which point
we will be able to remove the UI instances from the unit tests for those
commands.