[Feature] flexibly generate atlases with different resolutions

[alessandrofelder]

Is your feature request related to a problem? Please describe.
When we currently (re)generate e.g the Kim atlas, which we provide at 4 different resolutions, we have no good way of testing the packaging script at just one resolution.

• We could pass the resolution with an argument parser, as implemented for the Kim atlas recently (Fixes to Perens and Kim mouse atlases #271).
• We could temporarily and locally replace a for-loop with a hard-coded number.

Describe the solution you'd like
A flexible solution, that ideally doesn't involve an arg parser (I think)? But I'm not sure.
Maybe at least re-use argument parser code across atlases that we want to provide

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

Additional context
None