Handle `include` tag in `generate_benchmark_scripts()`
PRJ files can contain an
include tag that directs to an external
XML file, which contains additional tags.
Actually, this tag is read in
Yet, there is no procedure how the respective call is created in
generate_benchmark_scripts() right now.
For example, the benchmark
circle_1e1_axi.prj contains an
include tag to refer to process tags in an external file.