make clippy a bit happier

[savente93]

Resolve Clippy warnings throughout the repo. No actual functionality is changed. I do think it is nice and slightly cleaner in a few instances. I just think it is a bit neater to conform to the standard linter. Hope this will be an easy merge.

Sanity check:

• [x ] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Code changes

This is a very insubstantial change, and for the vast majority consists of removing unnecessary borrows or using lazy versions of functions that call closures (e.g. unwrap_or_else vs or).

• [x ] Are you doing the PR on the next branch?

[Keats]

Thanks a lot!