input: Write a function to scrape the table from the given URL and extract the planets information (name, mass, and distance from the sun). The function should return a list of dictionaries where each dictionary contains the extracted information for a planet. If the table or the required information is not found, the function should return an empty list.
  assert scrape_planets_info('https://en.wikipedia.org/wiki/List_of_gravitationally_rounded_objects_of_the_Solar_System')==[{"name": "Mercury", "mass": "3.3011\u00d710\u00b2\u2073 kg,,7", "distance_from_sun": "57.909 million km,,–"}, ...]
output: def scrape_planets_info(url):
      import requests
      from bs4 import BeautifulSoup
      
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      
      table = soup.find('table', {'class': 'wikitable'})
      if not table:
          return []
      
      rows = table.find_all('tr')
      planets_info = []
      
      for row in rows[1:]:
          cols = row.find_all('td')
          if len(cols) >= 4:
              name = cols[0].get_text(strip=True)
              mass = cols[1].get_text(strip=True)
              distance_from_sun = cols[2].get_text(strip=True)
              planets_info.append({
                  "name": name,
                  "mass": mass,
                  "distance_from_sun": distance_from_sun
              })
      
      return planets_info