28977 Fix const enum initializer error message

[alisabzevari]

Fixes #28977,

This is my first PR 😃
I updated the error message based on the suggestions in the issue and changed the baselines.

[DanielRosenwasser]

Sorry, now that I look at it, this is somewhat inaccurate because any computed enum is fair game:

enum E {
    A,
    B,
    C,
}

const enum F {
    // works
    A = E.A,
}

What about

const enum member initializers can only contain literal values and other computed enum values.

[alisabzevari]

Sure, I will change the message.

BTW, wouldn't it make sense to provide some link to a page with samples and more detailed description in every error message? This error message already contains 2 Typescript terminologies (const enum initializer, computed enum values) which make it hard to understand. At least for me.

[DanielRosenwasser]

I think down the line that might make sense, but I'd rather not do this for only one error message. I could imagine that down the line, diagnostics had an "documentation" field or something like that.

[alisabzevari]

Exactly. This was an idea for all the error messages. Should I create an issue?

[DanielRosenwasser]

Sure thing! We've been discussing it recently and aren't sure what the workflow should be like.