Add more services to statemachine example

[Yokozuna59]

Resolves #1257.

• validation

  • Validate unreachable states
  • Validate unused events

• code actions

  • If a state name doesn't start with a capital letter, replace it with capitalized name (look at the corresponding validation here)
  • Remove an unreachable state
  • Remove an unused event

• LSP

  • Formatter
    * [ ] RenameProvider (it's working fine)

I also validated commands with events and states.

I haven't implemented the full version of quick fix to make state name starts with capital letter yet. The current Langium LSP didn't implement such feature yet, so I'm not sure how to do it in a clean approach.

[Yokozuna59]

One more thing, how to double indent? Currently, the following code:

state ExampleState
    actions {
        commandOne
    }
end

Would be formatted to:

state ExampleState
    actions {
    commandOne
    }
end

I tried to do the following:

formatter.interior(bracesOpen, bracesClose)
    .prepend(Formatting.indent())
    .prepend(Formatting.indent());

But it didn't work.

[msujew]

I took a look at this, and this seems to be an issue in the formatter. This is probably something we want to fix in a separate PR.

[Yokozuna59]

I see, I think the outer indent (the one for state and end) overrides this one.
Or maybe it doesn't take the double indent in consideration.

[Yokozuna59]

Sorry for the wait, but I have applied the comments in this PR.

Although I don't know how to make the ECA test pass, I have created an account there, but previous commits are failing.

[msujew]

@Yokozuna59 Can you squash your commits? I believe the ECA tool has some weird issue with some of your commits. Maybe you might also need to remove the verification requirement on your commits? All of them (except for the merge commit) say that they are Unverified.

[Yokozuna59]

@msujew I squashed the commits and removed the commit verification, but the ECA is still failing.

[spoenemann]

@Yokozuna59 have you used exactly the same email address in your Eclipse account as in the Git commit?

[Yokozuna59]

@spoenemann Yes. Before rebasing and after creating the account, it showed that commits after that passed the test, but the original commits before creating the account still failed.