Since any version prior to v0.15.4-beta will not sync to the mainnet
chain, we can safely bump the minimum required version to that since no
older version will be running (properly) anywhere.
This is a follow up to #21. In this PR increase the fixed rate
denominator from 1e6 to 1e9 (a factor of 100x), which will allow us to
express a per-block lease rate for the smallest possible order (1 unit,
or 100k sats) over the longest possible lease period (6 months).
In tihs commit, we modify the order acceptance commands (llm submit ask
and llm submit bid) to take the final percentage rather than the fixed
rate. Historically we've seen that people find thinking in fixed point
arithmetic difficult. So instead of exposing this value, we now poll the
user for the amount their willing to pay or accept as yield for the
_entire duration_.
With this change, users only need to think about the lump sum coupon
payment rather than the internal fixed rate. This should also lend to
better price discovery as distinct orders may end up with the same
rate_fixed when converted at the end.
In addition to this change, we now show a break down of the order
parameters which includes the execution fee.
