Chore: add more clippy lints and apply suggestions

[orottier]

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Working towards #114

[b-ma]

Hum sorry, I guess there is a misunderstanding on my side on this point, as I constantly remove the per file clippy directives.

As I understood #114, I though we wanted to have a common config at the crate level. Could you elaborate on the methodology you want to follow and on the final set of directive we'd like to have, so I don't constantly break what you try to achieve in the long term?

[orottier]

Hey, no worries. I actually don't really have a plan currently so I never complained about it either. I'll try to come up with a strategy in the linked ticket so we can discuss it there

[b-ma]

In the mean time, maybe having some comment (e.g. // clippy::do-not-remove-clippy!) on the ones that must be there