Serialize Data-* Attributes

[Archmonger]

Current Situation

Currently, data attributes are not serialized, such as in the context of events.

Proposed Actions

Serialize Data attributes and pass this information into the Python portions of IDOM.

See original discussion.

Work Items

See above.

[Archmonger]

This one is kinda lower priority, since there's typically ways of working around this. In the interest of not perpetually overloading the scope of v1, this should probably be handled in v2.

[Archmonger]

Closing in favor of #1196