PGO dataset.py: Rotation/translation swapped in relative pose noise

## 🐛 Bug

Rotation and translation noise are swapped in the PGO noise addition for `pose_graph/dataset.py`. Link to the [relevant location](https://github.com/facebookresearch/theseus/blob/cd2fc2c415b7e6bc41c963b98689c786edeacc1e/theseus/utils/examples/pose_graph/dataset.py#L282). The se3 tangent vector should be `[noise_trans, noise_rot]` but here it is `[noise_rot, noise_trans]`. Submitting a simple pull request.

Start at theseus/utils/examples/pose_graph/dataset.py around line 282, the linked location for relative pose noise. Check the SE(3) tangent-vector ordering against the issue description, then run the relevant pose-graph example or available tests. Done means rotation and translation noise are applied to their intended components without changing unrelated behavior.

Written by the indexing model from the issue text.