This commit changes the way we shell out externals when using the `"$it"` argument. Also pipes per row to an external's stdin if no `"$it"` argument is present for external commands.
Further separation of logic (preparing the external's command arguments, getting the data for piping, emitting values, spawning processes) will give us a better idea for lower level details regarding external commands until we can find the right abstractions for making them more generic and unify within the pipeline calling logic of Nu internal's and external's.
* Put a sample_data.ods file for testing
This is a copy of the sample_data.xlsx file but in ods format
* Add the from-ods command
Most of the work was doing `rg xlsx` and then copy/paste with light editing
* Add tests for the from-ods command
* Fix failing test
The problem was improper filename sorting in the test `prepares_and_decorates_filesystem_source_files`
