Add additional info functions to poppler-document object in CPP

Allow querying if the document has Javascript and which type of forms it contains
7 jobs for cpp-api in 18 minutes and 34 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #1184214
build

00:08:37

passed #1184003
build_android

00:01:50

passed #1183999
build_clang_libcpp

00:09:57

passed #1184002
build_clazy

00:03:04

passed #1184001
build_mingw64_fedora

00:05:49

passed #1184000
build_ubuntu_16_04

00:02:00

failed #1183998
build

00:00:13