Clean up custom console output with utils

[cassaundra]

Use utility functions to simplify styling and make the existing styling and indentation more consistent.

A few instances of manual styling remain:

• In the deprecation messages in set_version.rs and upgrade.rs (these could use an aesthetic pass too though, since they look out of place).
• In the feature activation list of set_version.
• In cargo add, per review discussion.

This also serves as a step towards #682, as these utilities functions are similar in form to Cargo's shell output.

[epage]

Thanks! I hadn't even considered aligning the printing

[cassaundra]

Okay! I wasn't originally planning on directly mimicking Cargo's internal implementation of the shell utilities, but seeing the merits of that, I renamed the functions as requested. I also added a justified parameter, and applied that to shell_warn.

Per your request, I also reverted all changes made to cargo add. It turns out the only instance of an uppercase message is inside cargo add, for what it's worth:

cargo-edit/src/bin/add/add.rs

Lines 582 to 585 in fdb12eb

	unrecognized_features_message(&format!(
	"Unrecognized features: {:?}",
	unknown_features
	))?;

[epage]

Last things

[cassaundra]

Okay! I've cleaned up the git history quite a bit. Should be good to merge.

[epage]

Thanks!