Add support for grid column alignment

[5HT2]

Having support for aligning a column to the right of the given width would be much appreciated!

The docs for the original repo impl can be found here: https://docs.rs/term_grid/latest/term_grid/enum.Alignment.html

[tertsdiepraam]

I removed this from the original because it turned out not to be important for uutils. I don't think we should add it back in because it is mostly useful for a layout with a fixed number of columns. What kind of use case do you have where you want to align a column without a fixed number of columns? Or would you like to align all items across the whole grid?

[5HT2]

The latter, I'd like to align items across the entire grid, basically.

For example, I'd like to be able to have a right-fixed column with a fixed max width, and fill the left-to-right columns with an auto-fit.