feat: add defmt and add rust-version (MSRV) of 1.62

[elpiel]

Something to note: defmt still uses bitflags@1 which adds some derive macros when bitflags! macro is used. defmt also defines their own bitflags! macro to derive Format which leads to the cfg_attributes when the defmt-03 feature is not enabled

[elpiel]

@eupn should be ready for review. Had to tweak the CI and add the MSRV.

[elpiel]

It seems that this feature was stabilized in 1.62 maybe we can bump the MSRV to that or even later version?

error[E0658]: deriving Default on enums is experimental
--> /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/defmt-parser-0.3.3/src/types.rs:3:24
|
3 | #[derive(Clone, Debug, Default, Eq, PartialEq)]
| ^^^^^^^
|
= note: see issue #86985 rust-lang/rust#86985 for more information
= note: this error originates in the derive macro Default (in Nightly builds, run with -Z macro-backtrace for more info)

[eupn]

It seems that this feature was stabilized in 1.62 maybe we can bump the MSRV to that or even later version?

Sure let's bump the MSRV.

[elpiel]

Pfff... Now it seems that nix requires bigger MSRV but it's only for the examples.

Maybe we can downgrade one of the dependencies to allow the examples to run on 1.62? It's a linux-embedded-hal dependency and that' our only option for embedded-hal@1.0 version of the crate