fix: BadLocationException can be thrown before we check the document version

[FlorianKroiss]

Unfortunately, the fix in #1444 was incomplete, because the call to normalizedOffset can also run into a BadLocationException if the document has changed since the job was scheduled:

org.eclipse.jface.text.BadLocationException: null
	at org.eclipse.jface.text.AbstractDocument.getChar(AbstractDocument.java:774)
	at org.eclipse.core.internal.filebuffers.SynchronizableDocument.getChar(SynchronizableDocument.java:236)
	at org.eclipse.lsp4e.operations.highlight.HighlightReconcilingStrategy.normalizedOffset(HighlightReconcilingStrategy.java:332)
	at org.eclipse.lsp4e.operations.highlight.HighlightReconcilingStrategy.collectHighlights(HighlightReconcilingStrategy.java:213)
	at org.eclipse.lsp4e.operations.highlight.HighlightReconcilingStrategy.lambda$0(HighlightReconcilingStrategy.java:138)
	at org.eclipse.core.runtime.jobs.Job$2.run(Job.java:187)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

Fix: Let normalizedOffset throw the BadLocationException and move normalizedOffset() after the document modification check and inside the try block, so that the BadLocationException is properly handled.