Add internal API to expose edge temporal properties by row

There is currently no API which exposes edge temporal properties by row. This can become a problem in persistent graphs, specifically persistent graphs with a windowed filter for example. In this case, we need some special logic to get the correct temporal properties, especially at the beginning of the window. Namely, we need to account for the properties that have persisted into the window from the base graph, which are currently injected at the start of the window. Currently, this logic exists in the serialization of ParquetTEdge in raphtory/src/parquet_encoder/model.rs (other places may implement this as well). This logic should be moved and centralized in a more sensible place.

Start by reading the ParquetTEdge serialization logic in raphtory/src/parquet_encoder/model.rs, focusing on how temporal properties are injected at the beginning of a window. Inspect other locations that may implement similar logic and determine where a centralized internal API should live. Done means edge temporal properties can be exposed by row, including properties persisted from the base graph.