Merge bitcoin/bitcoin#19690: util: improve FindByte() performance

72efc26439 util: improve streams.h:FindByte() performance (Larry Ruane)
604df63f6c [bench] add streams findbyte (gzhao408)

Pull request description:

  This PR is strictly a performance improvement; there is no functional change. The `CBufferedFile::FindByte()` method searches for the next occurrence of the given byte in the file. Currently, this is done by explicitly inspecting each byte in turn. This PR takes advantage of `std::find()` to do the same more efficiently, improving its CPU runtime by a factor of about 25 in typical use.

ACKs for top commit:
  achow101:
    re-ACK 72efc26439
  stickies-v:
    re-ACK 72efc26439

Tree-SHA512: ddf0bff335cc8aa34f911aa4e0558fa77ce35d963d602e4ab1c63090b4a386faf074548daf06ee829c7f2c760d06eed0125cf4c34e981c6129cea1804eb3b719

src/test/fuzz/buffered_file.cpp

@@ -53,7 +53,7 @@ FUZZ_TARGET(buffered_file)
                         return;
                     }
                     try {
-                        opt_buffered_file->FindByte(fuzzed_data_provider.ConsumeIntegral<uint8_t>());
+                        opt_buffered_file->FindByte(std::byte(fuzzed_data_provider.ConsumeIntegral<uint8_t>()));
                     } catch (const std::ios_base::failure&) {
                     }
                 },