add 'retrigger_joker_cashout' feature

[vitellaryjr]

allows jokers that give end-of-round cash to be retriggered by other jokers. locked behind a new optional feature, as to not immediately change behavior of existing mods

the retrigger_joker context will receive a cashout_retrigger argument when this is being performed; if mods want to explicitly prevent this feature, they can check and not context.cashout_retrigger in their retrigger joker's code.

Additional Info:

• I didn't modify api's or I've made a PR to the wiki repo.
  • to-do: update available features (can do this myself if this gets merged)
• I didn't modify api's or I've updated lsp definitions.
• I didn't make new lovely files or all new lovely files have appropriate priority.