Wrap Click results (`Result`) with a new class (`CLIResult`), which
includes:
1. Assertion statements.
2. Logic for formatting and printing a Click result.
3. Invocation arguments, which are missing from the original `Result`
class.
- display_banner() was only displayed in CLI mode so it makes sense
for it to be in the CLI.
- get_version(), was mvoed to util since it is a static function
that is needed in multiple parts of the application.
originally PDF files were included for these edge-cases but in
reality all we want to test is the filename itself. So it reduces
repo size if we have them generated dynamically.
