Limit functions don't work on LScene

Not sure if this is intended behavior: https://discourse.julialang.org/t/makie-xlims/56417/2

`xlims!` and friends are defined for `Scene` and `Axis` but not `LScene`. I would expect this to work:
```julia
_, axis, _ = lines(x, y, z, linewidth=0.5, show_axis=false)
xlims!(axis, 1.05,1.95)
ylims!(axis, 1.05,1.95)
```