Render dataset in specific order.

[galachad]

Currently, the order of rendered dataset is base on the names from object, e.g. tblist is order by tblist.

We need to add custom dynamic ordering, that can be changed in the cohort.

I'm not sure if this should be added in shinyCohortBuilder or cohortBuilder. This change should not impact any buisness logic, only the order of dataset display in shinyCohortBuilder.