Support of "expanded" monomer option

[AlexeyGirin]

Indigo side is here: epam/Indigo#2790

Requirements

1. If a monomer is expanded in small molecules mode, that option should be stored by Ketcher (and passed on to Indigo when appropriate - export/layout...).

2. If a monomer is manipulated (rotated, flipped) in small molecules mode, the manipulations should be stored by Ketcher even if the monomer is later collapsed (and passed on to Indigo when appropriate - export/layout...).

3. When going back to macromolecules mode, the monomer should still be represented with a symbol (sequence) or with a shape (flex/snake).

While testing this task, it's also necessary to test the following task:
epam/Indigo#2788