feat: [UTP-242] Make subnet replica version available to canisters via management API

[michael-weigelt]

This PR is a follow-up to either https://github.com/dfinity/ic/pull/2082, https://github.com/dfinity/ic/pull/2201 or https://github.com/dfinity/ic/pull/2248

It makes replica_version available via a management canister call as specified here.

[alin-at-dfinity]

FYI, you can create a PR on top of a branch other than master (in this case, I believe mwe/subnet_metrics_exe from #2248 would have been appropriate).

Then the change can be reviewed before said branch is merged to master. And when it is merged, then GitHub automatically rebases and changes the base branch to master.

[michael-weigelt]

@alin-at-dfinity

when it is merged, then GitHub automatically rebases

This I did not know, nice.

[dsarlis]

Added also Martin as a reviewer explicitly for spec compliance check.