Modal multiple submission bug

**Ready to merge**

Fixes multiple submissions for all important modals (everywhere we're creating debits or credits).

I'm in-progress on fixing multiple submission for the other modals, but they're less urgent. Those include adding stuff (bank accounts, cards, callbacks), removing stuff (same list), editing things (marketplace, customer info), verifying bank accounts, and downloading transactions. Feel free to merge this now and I'll submit the other modals in a separate PR later today.