Feature request: cbt read cells-per-row option

[icio]

Is your feature request related to a problem? Please describe.

I was trying to test how BigTable behaves when you send a zero cells-per-row row filter and reached for cbt read to construct a request but it didn't have the option.

Describe the solution you'd like

cbt read cells-per-column=n

Describe alternatives you've considered

Hand-rolling the request myself using the SDK.