plot_fit_tibble: Assemble data from a fit tibble and plot
In MattWiener/heemodFits: Using Survival Fits with Heemod

Assemble data from a fit tibble and plot

1 2	plot_fit_tibble(fit_tibble, treatment, set_name, type, set_for_km = "all", B_ci = 100, scale_time = 1, ...)

`fit_tibble`	the output of `survival_fits_from_tabular()`.
`treatment`	the treatment for which we want to plot.
`set_name`	subset name for all but the Kaplan-Meier curve.
`type`	PFS or OS
`set_for_km`	subset name for the Kaplan-Meier curve.
`B_ci`	number of simulations to use for confidence intervals for `flexsurvreg` objects; becomes the `B` of `flexsurv::summary.flexsurvreg()`
`scale_time`	times are multiplied by this. So if your fit was done on a time scale of days, and you want to plot by weeks, set this to 1/7
`...`	additional parameters to pass to `plot_fit_data()`