Dynamic channel creation fees

[filefilegoadmin]

Currently, channel creation is set to be a fixed fee. The idea is to be able to adjust it by the validator nodes.

Things to have in mind:

1. TXs containing channel creation payload are validated if they contain the right amount
2. This means we need to keep track of the changed fees so we can apply them properly for a node that is syncing from the beginning to avoid failed validations.

[filefilegoadmin]

This can be done by saving the last fee in the db which then can be mutated from the tx that includes the changes from the validators. This way all the transactions that contain the channel operations, will be validated properly.

To conclude, a state for currentChannelFees must be defined with a default value, and each time its change this value is updated

[filefilegoadmin]

Concerns:

Lets assume that Mempool contains 3 tx that create a channel, and the fee is "0x1", and before a new block is sealed the channel creation fees are altered by the validators, if the state of the channel fees is updated before the rest of the transactions have mutated the state, then we could have inconsistent state meaning that their transactions might be invalid.

One solution is to always add transactions that contain the channel fee changes at the end of the list