Libva 2.19.0

• docs: fix references and descriptions snf focyhrn mstkup
• ci: add build docs test
• win: change default driver search path to bindir
• win: rely on compiler to define link names
• add: Add mono_chrome to VAEncSequenceParameterBufferAV1
• add: Enable support for license acquisition of multiple protected playbacks
• fix: year for version 2.18.0 in NEWS
• fix: use secure_getenv instead of getenv
• trace: Improve and add VA trace log for AV1 encode
• trace: Unify va log message, replace va_TracePrint with va_TraceMsg.