De-duplicate QIOPipe implementations

We currently have three copies of the QIOPipe class:

$ git grep --recurse-submodules  -we QIOPipe | cut -d: -f1 | uniq | while read FILE; do dirname $FILE; done | uniq
qtdeclarative/tests/auto/qmlls/lifecycle
qtlanguageserver/tests/auto/qlanguageserver
qtpositioning/src/plugins/position/nmea

They all differ ever so slightly. We don't need to put it into a library, but it would be nice to have one central source and not three copies. Or, if we have three copies, designate one to be the primary, and make sure its location is clearly communicated in the other copies.