Add function for default column definitions

[ohjakobsen]

For reactable tables, we could add a utility function that defines global definitions for columns that are used in multiple tables. This will reduce complexity in code, increase consistency and keep code more DRY.

Here is an example of such a utility function:

default_columns <- function(columns, column_definitions = list()) {
  defaults <- list(
    client = colDef(name = 'Klient', maxWidth = 100),
    comp_reg_no = colDef(name = 'Org.nr', maxWidth = 100),
    voucher_no = colDef(name = 'Bilag')
  )
  column_list <- defaults[columns[columns %in% names(defaults)]]
  return(modifyList(column_list, column_definitions))
}

Originally posted by @ohjakobsen in #106 (comment)