Create a proposal type to be able to reinitialize feemarket base fee

[thomas-nguy]

Proposal:

Given the nature of the feemarket, it would be possible that the network reach some absurd value due to the lack of traffic or congestion for a long duration, especially if the feemarket parameters are not choosen properly in the first place)

In that case it would be useful to be able to reajust the feemarket parameter through a governance proposal