[feat] Gadget Metadata

[shekohex]

This PR introduces an easier way to define your gadget sources in your Cargo.toml

It is not, However, a new way that we created, it is actually encouraged by Cargo to let other tools embed extra metadata that could be later on used by these tools, see: for more information.

In our case, you can define your gadget metadata related to where we find your gadget binaries like the following:

[[package.metadata.gadget.Native.sources]]
owner = "webb-tools"
repo = "incredible-squaring"
tag = "0.1.0"
binaries = [
    { arch = "Amd64", os = "Linux", name = "amd64-linux-incredible-squaring-gadget" },
    { arch = "Arm64", os = "Linux", name = "arm64-linux-incredible-squaring-gadget" },
]

---

Open Questions

• In Github CI, we should update the blueprint.json with the SHA256 of the release binaries, that could be a separate task, or we could create our own github action.
• Blueprint Specification (blueprint.json), potentially, should be attached to each github release.

[drewstone]

What task is this for?

[shekohex]

What task is this for?

Ah, This PR is to replace the old task defined here: #253

[drewstone]

One more CI task to fix.

[shekohex]

@drewstone it is failing since #246 I would mention @Serial-ATA here to investigate more in his PR.

[Serial-ATA]

Yeah, #246 wasn't tested on the CI changes in #284. I'll take a look.