Axes updates for plots

[faizan-khan-iit]

Currently, (through this PR) we have axes updates for most geoms. The computation for data subsets to be used during updates is done in the compiler. This works for most cases, but due to the limitations of the compiler, it does not work properly for some examples: https://github.com/tdhock/animint-examples/blob/master/examples/chip.seq.R#L247

We want axes updates to handles all the cases of single selection variables. One possible solution, as @tdhock suggested, would be to move the whole computation to the renderer, since there seems to be no efficient way to handle this in the compiler.

Any other suggestions?

[tdhock]

thanks for creating an issue for this