Added HostInfo output to Node response

[hopleus]

• have read the CONTRIBUTING.md file
• raised a GitHub issue or discussed it on the projects chat beforehand
• added unit tests
• added integration tests
• updated documentation if needed
• updated CHANGELOG.md

Usecase

As an administrator, I want to see the information that is available only in HostInfo, for example, the version of the client's TailScale, the OS name, its version, etc.

[hopleus]

@juanfont, I saw your comment #1205 (comment) but I think that adding the base fields from HostInfo will not affect the HeadScale in any way, because it is unlikely that TailScale will change the fields used in any way

[kradalby]

Quoting the issue referred above:

After discussing it with @kradalby, we reckon it would be safer/saner for Headscale if you just marshal the Machine.HostInfo as a string into gRPC, rather than transforming it into a proto object in Headscale. This way, if something changes (and it might from Tailscale side) Headscale would not be affected.

We cannot maintain all these field hand typed into the API, however just marshalling it as JSON and then unmarshalling it on the other side using tailcfg.Hostinfo would be fine.

If this is implemented, it should also be part of the JSON output of headscale nodes list --json and it should have integration tests to verify the output.

As mentioned in our contribution guidelines, all contributions needs tests and there are a few more tickboxes that has not been addressed.

[hopleus]

Quoting the issue referred above:

After discussing it with @kradalby, we reckon it would be safer/saner for Headscale if you just marshal the Machine.HostInfo as a string into gRPC, rather than transforming it into a proto object in Headscale. This way, if something changes (and it might from Tailscale side) Headscale would not be affected.

We cannot maintain all these field hand typed into the API, however just marshalling it as JSON and then unmarshalling it on the other side using tailcfg.Hostinfo would be fine.

If this is implemented, it should also be part of the JSON output of headscale nodes list --json and it should have integration tests to verify the output.

As mentioned in our contribution guidelines, all contributions needs tests and there are a few more tickboxes that has not been addressed.

Replaced with marshaling in JSON (protobuf.Struct).
Now, in the api, as well as through the cli, what is stored in the database will be output, without any processing