[Proposal] tax on minting and selling, not buying

Summary
3% sale tax on luna and 5% mint tax on ust, put the collected tax (usd) back to reserve pool for backing ust up.

Motivation
The taxation proposal seem to gain some traction and overall received very positive feedback. However we should not tax on purchase to encourage buy. The death spiral happened because of the hyperinflation.

Proposal
Everybody wins. Luna will be burned on future purchases no one will have to be killed for others to live. luna goes up or at least don’t die again. Build up the emptied reserve for ust bags.