Update codebase to use latest dependencies and idioms

[ErichDonGubler]

This large set of commits was a fun side-project of mine for a while now. These commits are divided by minimum version of Rust necessary to make subsequent dependency updates work in order to make grokking them straightforward. Feel free to be picky about what you want to keep, but I've tried to be as minimal as I thought prudent while still netting nice gains for maintenance.

Each individual commit has had cargo test done locally and then had CI run against it. There should be only be concerns about where one wants to draw the line in terms of minimum Rust support versus how up-to-date one wants to be with "modern" Rust.

Thanks for making this great tool. I hope that this makes your life easier. :)

[kstrafe]

This issue has been open for more than a year, is the project dead?

[xmo-odoo]

@BourgondAries

This issue has been open for more than a year, is the project dead?

Yes, Daniel gave up a while ago. I thought I had a departure post stashed somewhere but apparently not.