Issue

Closes #154

Description

For column mapping at the moment, grouping variables are selected manually by the user. However it would be useful if some columns are automatically selected if they are present in the data.

Main columns used for grouping:
TRTA
TRTAN
ACTARM
TRT01A
TRT01P
AGE
RACE
SEX
For pre-clinical: GROUP

Definition of Done

The requirements for the feature to be complete:

• Automatic selection of above columns in the 'Grouping Variables' selectInput in the Mapping section.
• If the columns are not present, input box still works as normal and columns can be manually selected
• If some but not all of the columns are present, the ones included should be automatically selected with no issues.

How to test

Mapping and Filters section -> Grouping Variables

Contributor checklist

• Code passes lintr checks
• Code passes all unit tests
• New logic covered by unit tests
• New logic is documented