clippy: fix new warnings

[senekor]

Most of the warnings relate to idiomatic format strings. I think these warnings were introduced with Rust 1.67.

variables can be used directly in the `format!` string
for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
`#[warn(clippy::uninlined_format_args)]` on by default

There is one other warning I fixed about lifetimes that can be elided.

There are still a couple warnings about a new function without a default implementation. I didn't do anything about those because it seemed unclear to me what the best thing to do is.

[github-actions]

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[ErikSchierboom]

@remlse I can't re-open this PR. Could you open another PR?