Create numbered and bulleted lists

This PR aims to add the creation of lists in a document. This only aims to support numbered and bulleted lists and not image bullet lists for now.

# TODO
* [x] Editor UI buttons
* [x] Detect list style at selection
* [x] Ops for list insertion/removal
* [x] OT support
* [x] Convert selected text to a list or selected list back to text
* [x] Add feature flags and session constraints
* [x] Default styles for numbered and bulleted lists

I added this in based on whats documented here: http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html#attribute-style_list-style-name

To me it seemed like that if you changed to some other paragraph style that pointed to a different list style then you may need to refresh here.