Include `basisOfRecord` in default columns returned by `atlas_occurrences()`

To improve user's ability to decide which data is best for their question, one very helpful column is `basisOfRecord` which supplies info about the type of observation (e.g., human observation, preserved specimen). This column is important enough for user's initial data exploration that it should be included in `group = "basic"` columns returned by `galah_select()` + `atlas_occurrences()`.