add option to force inclusion of both legendaries

[silenroc1]

associated with issue #1

• adds checkbox for option to select both legendaries
• extends js PoK checks to this checkbox
• extends functionality of counting number of wormholes and legendaries for this option

Disclaimer: only tested with a temporary save/get draft option from a local file instead of the draft saved online as in the live version.

[shenanigans-be]

Hi @silenroc1, thank you so much for your contribution! It solved the problem perfectly, but I went in a different direction, including reshuffling the configuration options a bit.

[silenroc1]

Thanks a lot, I understand you solved it more generically!