Introduce menu for column reordering

[brownsarahm]

This suggested deletion of content line 229 is part of the instructor training checkout process. I know the lesson is already packed, but as the dataset is so big please consider introducing the drop down menu under 'All' and introduce how to reorder the rows. I'll happily help with this addition.

Originally posted by @K05lowi in #82 (comment)

[brownsarahm]

Hi @K05lowi. About introducing a new feature, we have several issues about the number of columns, are you recommending a way to fix that? or truly about the rows? If it's about the columns, I would love that PR!

If about rows, can you clarify the motivation to reorder the rows besides the filtering that is in the lesson? That will help decide if that addition is worth overstuffing (and possibly cutting something else).

[bencomp]

I think this suggestion may indeed be about the "Reorder/Remove columns" menu, as a proposed solution to deal with the large number of columns mentioned in #35 (and other issues). I would also like to have this in the lesson. It should probably go into episode 2, just after creating the project when learners are introduced to the large number of columns and its implications for working with this dataset in OpenRefine. However, episode 2 is already very long, so it would help to balance the contents across episodes.

[bencomp]

I demonstrated the column reordering / removing dialog today at the beginning of the OR lesson.
It was very easy to show that you can move specific columns to certain positions, as well as remove columns, but I relied on knowing which columns were going to be used later in the lesson to randomly remove three columns and move two columns to the left. There must be better ways to introduce it.

[bencomp]

From now on I'm assuming this is about the menu for column reordering and removal (and edited the issue title to reflect that).