Implementation of variable mint fee

[ghost]

Technical Specification
Background document for reference

[ghost]

@greenbookwebb @issy-fleming follow up question from @mynameuhh and @Paul4912 is "What changes need to made to the burn fee, if any"?
Do we need to remove burn fees entirely or are they to be set to a flat fee on deployment?

[CalabashSquash]

How do y'all do it? Do y'all just check in every now and then, or do y'all have push notifications?

Yeah I raised this with rogue fenix while he made this github discussion, because I knew you were not likely to see it but I'm not sure what his reasoning was.

[greenbookwebb]

The burn fee parameter may change in future (but it's very unlikely).

We will not be doing any complex self-updating mechanism for burn fee like we did for mint fee. It will just be fixed. @mynameuhh

[CalabashSquash]

Yep makes sense. TY

[CalabashSquash]

@greenbookwebb Do you want the mintFee itself to be modifiable by governance, or just the Change_Interval?

[greenbookwebb]

@mynameuhh both please