How can Google Sheets take a range of multiple columns and rows and stack or consolidate all the non-empty cells into one column? For this case, I want non-unique cells. Also, each cell in the range is a string that has commas and spaces so if needed, a special char will need to be as a delimiter.
There are several questions already that are about concatenating columns, but they are all concatenating the values of the columns and not the actual columns - something such as this sudo SQL statement such as
SELECT * AS single_column or if the range was not dynamic an equivalent SQL could use union such as:
SELECT col_a AS single_colum FROM foo UNION ALL SELECT col_b AS single_colum FROM foo UNION ALL SELECT col_b AS single_colum FROM foo ...