Do not bail-out if incorrect ranges are requested via DocumentSymbol

[cmaglie]

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• [X] The PR has no duplicates (please search among the Pull Requests before creating one)
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• [ ] Tests for the changes have been added (for bug fixes / features)

What kind of change does this PR introduce? If invalid ranges are requested in DocumentSymbol the language server will just ignore and log them.

What is the current behavior? A jsonrpc error is returned, making the language server unusable on some IDE.

What is the new behavior? The invalid range is just ignored.