Add Lifespeaker class

[alice-i-cecile]

Replacement for Wildshaper: same sort of good nature-y, controlling vibes, but with less complexity for the rest of the table.

To do:

• [x] build out 10 or so forms
• [x] decide on if we need / want a subclass
• [x] add exploration features
• [x] add exploration feats

[alice-i-cecile]

Still not fully complete (especially the forms), but this is in a state where I think I'm happy to get reviews.