Remove insubstantial wisps

Remove insubstantial wisps

Insubstantial wisps aren't great monsters. Mechanically annoying, rarely
threatening in their vault usage, and not loreful enough to keep as a
rare vault decorating monster (compare toenail golems, which aren't
annoying and are very loreful).

After the Swamp overhaul these continued to appear in:

- assorted vaults (where they were generic electric/translocations theme
  or a now incorrect Swamp monster)
- the Foxfire card's effect list
- in the Abyss spawn list (as a Swamp guest)

None of these usages were particularly inspiring as the monster is not
great, so wisps are finally dissapated by this commit. The tile and
glyph info are retained to use as a dummy for player Wisp form.

For vaults:

- in Swamp and where they are a Swamp guest, they are replaced with
  will-o-the-wisps,
- in places where they are a generic electric threat, they are either
  removed or replaced with ball lightning (as appropriate),
- in places where they are a translocation theme piece, they are
  removed.

The Foxfire card no longer summons wisps, and just has a shorter list.

The Abyss spawn has been replaced with will-o-the-wisps.