printer: clean-up

Like a previous commit did for the grep-cli crate, this does some
polishing to the grep-printer crate. We aren't able to achieve as much
as we did with grep-cli, but we at least eliminate all rust-analyzer
lints and group imports in the way I've been doing recently.

Next we'll start doing some more invasive changes.

crates/printer/src/hyperlink_aliases.rs

@@ -1,7 +1,7 @@
 /// Aliases to well-known hyperlink schemes.
 ///
 /// These need to be sorted by name.
-pub const HYPERLINK_PATTERN_ALIASES: &[(&str, &str)] = &[
+pub(crate) const HYPERLINK_PATTERN_ALIASES: &[(&str, &str)] = &[
     #[cfg(unix)]
     ("file", "file://{host}/{file}"),
     #[cfg(windows)]