Gretel-synthetics

Automatically select character-based tokenization over SentencePiece if `vocab_size` is set to zero.

- Added a new Record Generator object to DF mode that generates entire records with custom validation
- Added custom `RuntimeError` when not enough training data is ingested
- Added ability for custom callbacks to capture epoch training details

Updated routines for generating data to return summary objects that have more detail on their properties.

Bugfix to ensure model weights are reset when a list of seed values is provided to the generator

⚙️ Smart seeding now supports a list of seeds. A list of seeds will yield a 1:1 mapping of seeds to generated lines. This is useful for synthesizing partial data tables

⚙️ When using DataFrame Batch mode, we now will write out the original Training DF header order to the model directory. When a model is loaded from disk, the resulting generated DataFrame will have the columns ordered the way they were in the training data.

🐛 When using DP mode. We (temporarily) will patch TensorFlow 2.4.x to utilize new Keras LSTM codepaths. This will be globally patched for Keras within the running Python Interpreter. This provides a drastic speedup when training a DP model.

📖 Doc updates for new seeding features.