ENH: Add unaliased pango column to 21L focus build

[corneliusroemer]

Context

Many aliases are popping up - confusing even me. Would be great to have also an unaliased column. This would allow for depth first sorting too - aliasing screws that up at the moment.

I'd keep BA unexpanded, so BA.2.75 -> BA.2.75, but BL.1 -> BA.2.75.1.1

Description

Should be possible to be added pretty easily by a small Python script in the workflow.

Can use pango_aliasor package.

Would make nextstrain/nextclade#984 less pressing

[corneliusroemer]

Can be tested on nextclade.dev with the BA.2 dataset (click on change and scroll down)

Particularly useful is sort - which will now sort so that aliased children are next to their unaliased parents!