Add safegards if UnitBase or UD value change

If a node lies about current amount base or UD value, based on that the sent amount in a transfer would be wrong.

This value can be double-checked on two nodes, or checked into a range of value.

It should be done at least on Ğ1 currency:

• 10 ≤ UDValue < 15: should be safe for one year at least
• 1 == base: should be safe for many years

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• Display everywhere where the amount is used in UD, mostly commands in the money group, display the conversion rate (DU = 10.XX Ğ1).