Our System check currently marks some PHP extensions as required that we actually don't need to require.
Those two are meanwhile built in PHP and can't be unavailable, so doesn't make sense to check them at all.
We indirectly already had symphony/polyfill-mbstring
included in the composer requirements, so the methods are always available. Checking for the extension is therefor not needed anymore, as everything should work without it. (We could also consider adding this as recommended module)
I've added symphony/polyfill-iconv
to ensure those methods are always available. We are actually not using that often, but the mbstring polyfill uses it and it allows us to remove the requirement. (We could also consider adding this as recommended module)
In addition I have marked or Common::mb_*
methods as deprecated and replaced their usage with the mb_*
functions directly, as those methods are actually doing nothing else. (We should do that for our plugins later as well)
refs #16650