feat: added optimizations

[michele-milesi]

Summary

Describe the purpose of the pull request, including:

• Added full_like(), zeros_like() and ones_like() where needed.
• Moved logging after training.
• Converted TensorDicts into python dictionary before training.
• Add _convert_="all" during the creation of the metric aggregator.
• Modified log_prob() method of TwoHotEncodingDistribution
• Removed distribution creation when not necessary in DreamerV1 and DreamerV2

Type of Change

Please select the one relevant option below:

• Optimization (non-breaking change that adds functionality)

Checklist

Please confirm that the following tasks have been completed:

• I have tested my changes locally and they work as expected. (Please describe the tests you performed.)
• I have added unit tests for my changes, or updated existing tests if necessary.
• I have updated the documentation, if applicable.
• I have installed pre-commit and run locally for my code changes.