We should expose a method to set/get local matrices of TransformNodes

Currently there’s no easy way to set/get local matrices to Tnodes
Tnode._localMatrix is not a public API and there’s no easy way to set local matrices directly…

Perhaps something like

getLocalMatrix() {
    return this._localMatrix.clone()
}
setLocalMatrix(m: Matrix) {
    this._localMatrix.copyFrom(m)
}

Might be helpful