GUI interface to define modules

[dalcde]

Work started in SpectralSequences/ext@dd60471

Todo

• Respect algebra option
• Support modules other than finite dimensional module
• Support Milnor algebra profiles + validation
• Validate actions before download
• Better user interface
  • Highlight class when hovering over
  • Display existing actions with coefficients some way
• Better integration with resolver
• Link to this from front page
• Better display of FD module (vary the sides of the bent action lines)