Edit metadata button panel

[hmiguim]

Edit metadata page button panel should:

• Cancel button:
  • If any change asks if user wants to discard the changes or not
  • In case of discard reset the data to its original state
• Clear button:
  • Clear the changes made by the user
• Save:
  • Warn the user that saving will alter the metadata.xml file inside the SIARD
  • Warn that the process can take some time