Clippy lints, fix deprecation warnings

[atezet]

Went ahead and fixed some clippy lints and deprecation warnings. Might break backwards compatibility, so maybe merge this before bumping the version to 3.0

[spenserblack]

I'm not seeing anything that would be breaking, so it should be good.

[spenserblack]

@atezet All of the changes in cee0316 were generated with cargo clippy --fix, right?

[spenserblack]

Oops, only squash and rebase merging are enabled in this repo, so I can't add 4744838 to this PR. Nevermind.

[atezet]

I've added some pedantic rules that I use across my projects. The following are configured in my editor:

clippy::cloned_instead_of_copied
clippy::expl_impl_clone_on_copy
clippy::explicit_deref_method
clippy::needless_pass_by_value
clippy::no_effect_underscore_binding
clippy::redundant_allocation
clippy::semicolon_if_nothing_returned
clippy::trivially_copy_pass_by_ref
clippy::unnecessary_wraps
clippy::unused_async
clippy::unused_self
clippy::wildcard_imports