Unicode characters mess up text shadow

The bug

When a message contains any "special" unicode character, the text shadow offset is calculated wrongly causing the shadow to be misaligned. This makes it difficult to read text in some situations.

How to reproduce

/titleraw @a title {"rawtext":[{"text":"test message"}]}

→  Looks fine

/titleraw @a title {"rawtext":[{"text":"\ue000 test message"}]}

→  Shadow is wrong