[Task]: Implement logic to allow tx or not based on mana cost for the X slots

[begonaalvarezd]

Task description

Price per block increases linearly with number of slots, so the formula to be used for the safe-buffer is really just

extraMana = numberOfSlots * protocolParams.CongestionControlParameters().Increase * blockWorkScore

That will give you the increase in maximum possible increase in Mana cost over numberOfSlots

Todos:

• Calculate extra mana for the next 3 slots and add it on top of the mana cost
• When 3 slots pass, re-calculate
• Disable send button if there isnt enough available mana

[begonaalvarezd]

@cpl121 lets caluclate the buffer for the next 3 slots, and after that we have to update and recalculate the buffer again, and so like that