Update EOExtension to spec version 2.0.0

[philvarner]

EOExtension should be updated to 2.0.0. It's unclear to me what the best way to support both 1.x and 2.x is, and I don't know if we have a pattern for this established yet.

[jsignell]

There is an established pattern. The level of effort tends to depend on how much has changed in the extension. See #1359 and #1287 for examples