This lets users specify any possible pair of characters to remote text
from in the SDH filter as opposed to the old way which would
automatically map ( to ) internally.
Additionally, this fixes#16597 because the old implementation relied on
looping over a single string using strlen for matching chars. That
doesn't work because strlen loops over bytes and non-ASCII characters
can have multiple bytes leading to false positives since the bytes could
match. There's various ways to deal with this, but simply using mpv's
internal stringlist type sidesteps that problem.
Dudemanguy
b5c629fd12