Convert All Default Implementations on Enums to derive(Default)

[killianc3]

Checklist

• Run cargo clippy.
• Run RUSTFLAGS=--cfg=web_sys_unstable_apis cargo clippy --target wasm32-unknown-unknown if applicable.
• Add change to CHANGELOG.md. See simple instructions inside file.

Connections
Closes #3077.

Description
Since rust-lang/rust#101040, we can now mark enums as #[default], this replaces manual implementation where possible.

Testing
I ran the cargo test before and after the changes and nothing changed, so I guess nothing was broken because these are very simple changes.

[cwfitzgerald]

Code looks good, just need to change the msrv in the Readme and ci to be the latest needed for #[default]

[killianc3]

It seems that the minimum supported version is now 1.62.0. (https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1620-2022-06-30)

[cwfitzgerald]

Nice, not nearly as bad as I thought

[killianc3]

Yes, it's not so bad and it seems to have passed the test now. Should we add an entry to the changelog to say that the msvr has changed ? If so, I don't really know how and what to add, any ideas ?

[cwfitzgerald]

Look at last releases big announcements - I'd add a thing like that that just says what msrv we bumped to.

[killianc3]

Thank you ! I think it's pretty understandable as is, what do you think ?

[cwfitzgerald]

Thanks!