**What's the problem this PR addresses?**
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`workspace.locator` is quite useless and only creates confusion with
`workspace.anchoredLocator`.

At the moment, it's only used in places that need an ident, which
`workspace.anchoredLocator` can happily provide.

In the past, it was also used accidentally instead of
`workspace.anchoredLocator` before I fixed it in
#4937.

**How did you fix it?**
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Removed it since it doesn't provide any benefits. Its only actual use is
comparisons in `project.tryWorkspaceByLocator`, but nobody has ever
passed it to `project.tryWorkspaceByLocator` anyways.

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