Move utils/JSInfo.cc utils/JSInfo.h to core poppler

and add new JSInfo::scanJS() variant that returns
immediately after finding JS. This variant is used
by newly added PDFDoc::hasJavascript() method which
is in turn used by newly added poppler-glib function
poppler_document_has_javascript()
6 jobs for BUG_glib_has_javascript3 in 3 minutes and 31 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #3331762
build

00:03:31

passed #3331767
build_android

00:00:34

passed #3331763
build_clang_libcpp

00:02:45

passed #3331766
build_clazy

00:02:07

passed #3331765
build_mingw64_fedora

00:02:30

passed #3331764
build_ubuntu_16_04

00:01:56