text: Title: Cryptofeed unable to validate orderbook checksums of some symbols on ftx
  Body: **Describe the bug**
  Cryptofeed is unable to validate the orderbook checksums of some symbols on ftx.
  
  It looks like the exchange sometimes provides the prices in scientific notation (3.426e-5) which is not how they are stored, hence the checksums provided by the exchange are not the same ones calculated by cryptofeed.
  
  Could numpy help with this?
  
  
  **To Reproduce**
  Steps to reproduce the behavior:
  * Provide small code sample that reproduces the issue
  
  ```
  from cryptofeed import FeedHandler
  from cryptofeed.defines import L2_BOOK
  from cryptofeed.exchanges import FTX
  
  
  async def book(book, receipt_timestamp):
      pass
  
  
  def main():
      config = {
          "log": {
              "filename": "/dev/null",
              "level": "DEBUG",
              "disabled": False,
          },
      }
      f = FeedHandler(config=config)
      f.add_feed(
          FTX(
              config=config,
              checksum_validation=True,
              symbols=["SHIB-USD"],
              channels=[
                  L2_BOOK,
              ],
              callbacks={L2_BOOK: book},
          )
      )
      f.run()
  
  
  if __name__ == "__main__":
      main()
  ```
  
  * Provide any tracebacks, if applicable
  
  ```
  Traceback (most recent call last):
    File "/home/rich/.pyenv/versions/ltcm/lib/python3.9/site-packages/cryptofeed/connection_handler.py", line 69, in _create_connection
      await self._handler(connection, self.handler)
    File "/home/rich/.pyenv/versions/ltcm/lib/python3.9/site-packages/cryptofeed/connection_handler.py", line 119, in _handler
      await handler(message, connection, self.conn.last_message)
    File "/home/rich/.pyenv/versions/ltcm/lib/python3.9/site-packages/cryptofeed/exchanges/ftx.py", line 425, in message_handler
      await self._book(msg, timestamp)
    File "/home/rich/.pyenv/versions/ltcm/lib/python3.9/site-packages/cryptofeed/exchanges/ftx.py", line 301, in _book
      raise BadChecksum
  cryptofeed.exceptions.BadChecksum
  ```
  
  **Operating System:**
  Linux
  
  **Cryptofeed Version**
  ```
  pip freeze | grep cryptofeed
  cryptofeed==2.1.2
  ```
  (from pypi)
  