[Feature] CI improvements

[somehowchris]

Is your feature request motivated by a concrete problem? Please describe.

Todays ci pipelines only include native hardware as well as only nightly and stable build channels. To be sure that devs can go on and dev as well as run these we need to be sure to have support for the most common arch types. (not only x86)

Why this feature can't or shouldn't live outside of Rocket

CI is a central part of any project.

Ideal Solution

• Build and Test on x86 as well as common aarch64 (using cross)
• Build for msrv, stable, beta as well as nightly
• Use actions-rs with linting on check, fmt and clippy
• Use actions-rs with cargo-tarpaulin to generate codecov
• Use ci for doc generation
• Use ci for releases
• Use github deployments within ci

Alternatives Considered

A clear and concise description of any alternative solutions or features you've considered.

Additional Context

Add any other context here, for example, descriptions of elegant solutions in other software.

[najtin]

Use actions-rs with linting on check, fmt and clippy

If the PRs https://github.com/rocket-org/devise/pull/1 and https://github.com/rocket-org/figment/pull/3 go through, these actions are essential, at least on the respective projects.