111880aaf7e12a12f0797f1b19673e3d96328edd [test] Add coverage to estimaterawfee and estimatesmartfee (Ben Woosley)
Pull request description:
This adds light functional coverage to estimaterawfee - a subset of
the testing applied to estimatesmartfee, and argument validation
testing to both estimaterawfee and estimatesmartfee.
One valid estimatesmartfee signature test is commented out because it
fails currently.
Extracted from #12940
Top commit has no ACKs.
Tree-SHA512: 361a883457b28b2dc75081666e49d6dc6b5d76eed40d858abe2dd4f35ece152cf1f99c94480a91f42a896aa2a73cf55f57921316fe66970b2d7ba691a3b17e2d
