Merge bitcoin/bitcoin#33218: refactor: rename fees.{h,cpp} to fees/block_policy_estimator.{h,cpp}

1a7fb5eeee fees: return current block height in estimateSmartFee (ismaelsadeeq)
ab49480d9b fees: rename fees_args to block_policy_estimator_args (ismaelsadeeq)
06db08a435 fees: refactor: rename fees to block_policy_estimator (ismaelsadeeq)
6dfdd7e034 fees: refactor: rename policy_fee_tests.cpp to feerounder_tests.cpp (ismaelsadeeq)

Pull request description:

  This PR is a simple refactoring that does four things:

  1. Renames `test/policy_fee_tests.cpp` to `test/feerounder_tests.cpp`.
  2. Renames `policy/fees.{h,cpp}` to `policy/fees/block_policy_estimator.{h,cpp}`.
  3. Renames `policy/fees_args.cpp` to `policy/fees/block_policy_estimator_args.cpp`.
  4. Modifies `estimateSmartFee` to return the block height at which the estimate was made by adding a `best_height` unsigned int value to the `FeeCalculation` struct.

  **Motivation**

  In preparation for adding a new fee estimator, the `fees` directory is created so we can organize code into `block_policy_estimator` and `mempool` because

  a) It would be clunky to add more code directly under `fees`.
  b) Having `policy/fees.{h,cpp}` and `policy/mempool.{h,cpp}` would also be undesirable.

  Therefore, it makes sense to structure the it as `policy/fees/block_policy_estimator`, `policy/fees/mempool`, etc.
  Hence test file were also updated accordingly.

  The current block height is also returned because later in #30157 we log the height at which each estimate is made (at the debug log category of  fee estimation :) ). This feature is particularly useful for empirical data analysis.

ACKs for top commit:
  maflcko:
    re-ACK 1a7fb5eeee 🐤
  polespinasa:
    re ACK 1a7fb5eeee
  willcl-ark:
    ACK 1a7fb5eeee
  janb84:
    re ACK 1a7fb5eeee

Tree-SHA512: fef7ace2a9f262ec0361fb7a46df5108afc46b5c4b059caadf2fd114740aefbb2592389d11646c13d0e28bf0ef2cfcfbab3e659c4d4288b8ebe64725fd1963c0

src/wallet/coincontrol.h

@@ -7,7 +7,7 @@
 
 #include <outputtype.h>
 #include <policy/feerate.h>
-#include <policy/fees.h>
+#include <policy/fees/block_policy_estimator.h>
 #include <primitives/transaction.h>
 #include <script/keyorigin.h>
 #include <script/signingprovider.h>

src/wallet/feebumper.cpp

@@ -5,7 +5,7 @@
 #include <common/system.h>
 #include <consensus/validation.h>
 #include <interfaces/chain.h>
-#include <policy/fees.h>
+#include <policy/fees/block_policy_estimator.h>
 #include <policy/policy.h>
 #include <util/moneystr.h>
 #include <util/rbf.h>

src/wallet/interfaces.cpp

@@ -9,7 +9,7 @@
 #include <interfaces/chain.h>
 #include <interfaces/handler.h>
 #include <node/types.h>
-#include <policy/fees.h>
+#include <policy/fees/block_policy_estimator.h>
 #include <primitives/transaction.h>
 #include <rpc/server.h>
 #include <scheduler.h>

src/wallet/spend.h

@@ -6,7 +6,7 @@
 #define BITCOIN_WALLET_SPEND_H
 
 #include <consensus/amount.h>
-#include <policy/fees.h>
+#include <policy/fees/block_policy_estimator.h>
 #include <util/result.h>
 #include <wallet/coinselection.h>
 #include <wallet/transaction.h>

src/wallet/test/spend_tests.cpp

@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <consensus/amount.h>
-#include <policy/fees.h>
+#include <policy/fees/block_policy_estimator.h>
 #include <script/solver.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>