Function toMatlab

Convert a JS-idiomatic DlmFitResult to MATLAB DLM layout and names.

This function serves two purposes:

1. Name restoration: smoothed → x, deviance → lik, etc.
2. Axis transposition: time-major [n, m] → state-major x[state][time]

Use this for MATLAB DLM migration and for comparing against Octave reference output that uses MATLAB naming conventions.