simplify vortex implementation and use Pytorch Lightning for trainer.

Added

Pytorch Lightning training pipeline
registry class
model base class
add 'config.trainer.validation_interval' field with same functionality as 'config.validator.val_epoch'
add 'config.trainer.logger' field with same functionality as 'config.logging'
add 'config.dataloader.train' and 'config.dataloader.eval' field to support different args for train and val dataloader
support for bool value for logger config, with default logger use tensorboard logger
backbone base class
backbone class for main models

Changed

model_components is removed, and changed with model base class
deprecating 'config.seed', and move to 'config.trainer.seed'
deprecating stage argument in create_model
all defined backbones use backbone base class
removed various old features affected by API redesign: cli, predictor, pipelines