Fix some clippy lints and other minor adjustments

[0xdea]

I have fixed some clippy lints and applied some minor adjustments to the code. I've run tests and checked that no semver update is required, and I'm reasonably certain that my changes didn't break anything, but please see if they make sense.

You could catch some other clippy recommendations by adding something like this in Cargo.toml:

[lints.clippy]
all = { level = "warn", priority = -1 }
pedantic = { level = "warn", priority = -1 }
nursery = { level = "warn", priority = -1 }
cargo = { level = "warn", priority = -1 }
missing_errors_doc = "allow"
missing_panics_doc = "allow"
wildcard_imports = "allow"
enum_glob_use = "allow"
unreadable_literal = "allow"
multiple_crate_versions = "allow"
significant_drop_tightening = "allow"
must_use_candidate = "allow"

PS. My IDE (RustRover) has decided to introduce some formatting changes as well... If you don't like them, let me know and I'll undo them.