Merge bitcoin/bitcoin#27934: test: added coverage to estimatefee

d05be124db test: added coverage to estimatefee (kevkevin)

Pull request description:

  Added a assert for an rpc error when we try to estimate fee for the max conf_target

  Line I am adding coverage to https://github.com/bitcoin/bitcoin/blob/master/src/rpc/fees.cpp#LL71C52-L71C52

ACKs for top commit:
  MarcoFalke:
    lgtm ACK d05be124db

Tree-SHA512: dfab075989446e33d1a5ff1a308f1ba1b9f80cce3848fbe4231f69212ceef456a3f2b19365a42123e0397c31893fd9f1fd9973cc00cfbb324386e12ed0e6bccc

test/functional/rpc_estimatefee.py

@@ -36,6 +36,9 @@ class EstimateFeeTest(BitcoinTestFramework):
         assert_raises_rpc_error(-1, "estimatesmartfee", self.nodes[0].estimatesmartfee, 1, 'ECONOMICAL', 1)
         assert_raises_rpc_error(-1, "estimaterawfee", self.nodes[0].estimaterawfee, 1, 1, 1)
 
+        # max value of 1008 per src/policy/fees.h
+        assert_raises_rpc_error(-8, "Invalid conf_target, must be between 1 and 1008", self.nodes[0].estimaterawfee, 1009)
+
         # valid calls
         self.nodes[0].estimatesmartfee(1)
         # self.nodes[0].estimatesmartfee(1, None)