This bypasses the `spinner` package for the textual progress indicator for users
with the spinner disabled out of concerns for accessibility, specifically
with screen readers:
- The `spinner` package will continuously re-draw the screen. I wasn't
able to have this cause problems with my Mac screen reader, but it's
nonetheless a concern that other screen readers may not handle this
screen re-drawing well.
- The `spinner` package clears any progress indicator messages from the screen
when stopping the progress indicator or changing its label.
This is a problem because it interrupts screen readers and leaves no way
to recover what the loading message was by scrolling up in the terminal.
NOTE: this new implementation still interrupts the screen reader when
the a new label is printed, but it does not clear the screen. This makes
the loading messages recoverable, at least.
- Move env var evaluation to the factory defaults.
- Use only the label for the spinner instead of adding
"working..." every time. "working..." remains the default
when no label is provided.
