BSim: Add option to delete BSim databases

[gemesa]

Is your feature request related to a problem? Please describe.
Currently there is no simple way (e.g. a cmd line option in bsim or bsim_ctl) to delete a BSim database. In case of PostgreSQL we can work around this (see below). Not sure about H2 and Elastic as I dont use them.

Describe the solution you'd like
A generic dropdatabase or similar subcommand added to bsim which can be used to delete databases. The API is there (SQL and Elastic), it just needs to get exposed via a cmd line option.

Describe alternatives you've considered
Workarounds in PostgreSQL:

$ psql -U username -c "DROP DATABASE database_name;"

or

$ dropdb -U username database_name

Additional context
N/A