Simple method for column transformations before plotting.

Hello,

I often need to plot slightly different versions of my data depending on who’s requesting data from me. I was hoping for a simple way of transforming columns such that I don’t have to keep altering my dataframes for every plot.

Here's an example use case:

Original Plot: _probability_ as a **decimal**
```
demo_df = pd.DataFrame({‘value’:np.random.randn(50),‘probability’:np.random.rand(50)})
demo_df.hvplot.scatter(x=‘value’,y=‘probability’)
```

____________________________________

Desired: plotting the _probability_ as a **percentage** instead.
Something like this might be nice:
```
percent = hv.dim(‘probability’)*100
demo_df.hvplot.scatter(x=‘value’,y=percent,ylabel='probability_as_percentage')
```