fixSubtitleAlignment

Fixes alignment for cues with {\anX}, this is common for .vtt that should be parsed as .srt

WEBVTT

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{\an1}Label 1

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{\an2}Label 2

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{\an3}Label 3

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{\an4}Label 4

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{\an5}Label 5

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{\an6}Label 6

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{\an7}Label 7

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{\an8}Label 8

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{\an9}Label 9