Validate that the user has sufficient DAI balance before submitting listing

[juanmardefago]

Right now you can submit a listing without enough DAI to pay for the listing fee, which results in users being able to submit a listing that will fail and cost them ETH in gas fees anyways.

We shouldn't let them submit the listing if they don't meet the criteria for the listing to succeed, to avoid any unexpected economic issue for the end user.

[juanmardefago]

@nenadjaja not sure who's in charge of development on the everest site though, you probably know better than me :)