Additional `benchmark-storage` flags (#11004)

* Fix typos

* Enable overwriting handlebars template

* Optionally name json output or disable json altogether

* Don't write to json by default

* Include block id in handlebars output

* Include warmups for write benchmarks

* PR comments

* Drop unnecessary file extension

* Use more appropriate types

* Use more appropriate error message

* More use of more appropriate types

* Rework write benchmark warmups

* Run same benchmark for both read and write