Remove or improve TODO above ContactFormMessage entity in main.wasp file

[Martinsos]

What about that TODO to add functionality to allow users to send messages to admin, above ContactFormMessage entity? That confused me, I wasn’t sure if this entity is here stranded and missing further functionality, or there is some more functionality, but what is missing then? How will I know? Should I delete it? Is this TODO left for me, or was left by open-saas devs for themselves?

I suggest we either update the TODO in main.wasp to be more informative, or delete the ContactFormMessage entity for now till this is fully implemented (if indeed the rest of the functionality is missing).