Is your feature request related to a problem? Please describe.
today, I only see an option of passing a sql command to cockroach sql with --execute flag. I'd like to see an option to pass a file instead. Lack of this ability forces one to do bash trickery to pass a file like so cockroach sql --insecure --host=localhost:26257 --database="tabular_import" --execute="$(< import_statement.sql)

Describe the solution you'd like
a more convenient solution is to see an option to pass a file with a switch like -f

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.