Pyramid of images tiled visualisation proto

Typescript prototype using h5web and h5grove server to display large images with pre-computed pyramid of images stored in a hdf5 file.

Visualization component is working and interaction is fairly smooth when run locally for a 150kx150k data image of float16!

There is a few tweaks that will need discussion to make it neat:

• I use a hack to pass float16 from fetching to GPU texture through ndarray (it also needs a patch of h5grove to disable sanitize fo float16 arrays).
• I duplicated and modified HeatmapMesh to support float16 and to use ndarray as input rather than number[] to avoid unnessary copies in my case.

The component splitting also need rework, in particular to abstract data fetching to make in generic (i.e., not only support h5grove).

I need to prepare a file with data that can be put on bosquet.silx.org for demo purpose (and testing remote access to data).