This function accepts a list representing the result of an individual parent
recordset from a nested parent-child query where there are zero or more child
records to be joined to the parent. In this case the child and parent will be
bound together to return one complete tbl_df of the query result for
that parent record.
list_extract_parent_and_child_result(x)list; list of records parsed from JSON representing one
individual parent query record.
tbl_df; a data frame with each row representing a parent-child
record (i.e. at least one row per parent or more if cross joined with more
than one child record).