Improve max payment validation

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The max-payment field has a validation not to accept amounts above a "max" filter. But if the payment is set, and then the max-paymnet is lowered, the payment requested will be above the new "max" value. We need to improve validation in that case.

I tried different methods according to the quasar-input validation, but it looks like it's going to need more time invested to fix it. But validation needs to happen also on the chain side,

• if editing, and having the value pre-set above max (because max was updated), show an error and do not allow to submit until setting below max (see https://quasar.dev/vue-components/input#Validation)
• What should happen if claiming a payment above max-payment?
• Candidates can be reelected if having a payment request above max-payment?