Add a tokenizer for URLPatterns (servo#36362)

Not a lot of new tests start to pass because the actual parser is still
missing, so we're only passing tests for invalid inputs. The parser will
be added in the next PR.

This is part 3 of upstreaming the changes in
https://github.com/simonwuelker/servo/tree/urlpattern

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Signed-off-by: Simon Wülker <[email protected]>

Author: simonwuelker