This change will improve over CLI performance and "snappiness" as well as
substantially reduce our test times. Preliminary benchmarks show
`coder server --help` times cut from 300ms to 120ms on my dogfood
instance.
The inefficiency of lipgloss disproportionately impacts our system, as all help
text for every command is generated whenever any command is invoked.
The `pretty` API could clean up a lot of the code (e.g., by replacing
complex string concatenations with Printf), but this commit is too
expansive as is so that work will be done in a follow up.
This allows specifying a command to run that can output headers for
cases where users require dynamic headers (like to authenticate to their
VPN).
The primary use case is to add this flag in SSH configs created by the
VS Code plugin, although maybe config-ssh should do the same.
Ammar Bandukwala