Simplify match patterns to be more ergonomic

[yotamofek]

Some of the code in this crate is around a decade old, which means it couldn't use the ergonomic benefits afforded by RFC 2005 (which was stabilized around 2017 or 2018).

So now instead of doing match *thing { ref mut thing => { ... } }, we can just do match thing { thing => { ... } }.

See discussion here: #113 (comment)

[cuviper]

I admit I still have some lingering preference to be explicit, but I'm learning to live with it. e.g. as_ref and as_mut look like weird no-ops now, but with match ergonomics it really is translating the references. Oh well, not a big deal in the end.

Thanks!

[yotamofek]

I started learning rust after match ergonomics were stabilized and I feel the opposite - ref and ref mut always look really weird to me. Guess it's really a matter of what you're used to. :)