Reenable explode vertices

[miratepuffin]

In prior versions of Raphtory we were able to explode vertices as well edges, with the nodes being able to reference/communicate with their past and future selves. This functionality needs to be reenabled for our new APIs.

As an extension to the way this used to work, it would be good if these could be exploded at set increments instead of at every time point in their history - this discretises things making it easier to analyse a vertex at everyday etc.