Escape quotation marks in ConfigVersion.cmake.in files
This generates a file that contains a strings like
if("${PACKAGE_VERSION}" VERSION_LESS "${PACKAGE_FIND_VERSION}" )
instead of
if(${PACKAGE_VERSION} VERSION_LESS ${PACKAGE_FIND_VERSION} )
and therefore work also if PACKAGE_FIND_VERSION
is not defined, i.e. if the user wants to find the package without specifying the version, i.e.
find_package(AccountsQt5)
Without the quotation marks, this generates an "Unknown arguments specified" fatal error.