Added man pages for flow.

Generated using:

declare -A short_desc
short_desc['flow']='Eclipse compatible parallel reservoir simulator'
short_desc['ebos']='Eclipse compatible parallel reservoir simulator for research'
for key in "${!short_desc[@]}"; do
           help2man -h "-h" --version-string="2021.04" --no-discard-stderr -n "${short_desc[$key]}" -N $key >\
           $key.1
done

Gbp-Pq: Name 0002-Added-man-pages-for-flow-and-ebos.patch

CMakeLists.txt

@@ -487,3 +487,6 @@ if(HAVE_FPGA)
   ExternalProject_Get_Property(FPGA_library binary_dir)
   target_link_libraries(opmsimulators PUBLIC ${binary_dir}/fpga_lib_alveo_u280.a)
 endif()
+
+install(DIRECTORY doc/man1 DESTINATION ${CMAKE_INSTALL_MANDIR}
+  FILES_MATCHING PATTERN "*.1")