* Batch benchmarks together with `*` notation.
* Fix short structopt conflict
* Return error if `batches` is empty
* Move fast benchmarks macro into `frame_benchmarking` (#5445)
* Move macro into `frame_benchmarking`
* Update docs
* Extra line
* Return error if `batches` is empty
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>