The `register` naming is not very clear, and also the meta-programming
in the previous approach erased type information. By having a shared
based class, implementing a custom tileset is much nicer:

```py
from dataclasses import dataclass

import higlass as hg
from clodius.tiles import cooler

@DataClass
class MyCustomCoolerTileset(hg.Tileset):
    path: str
    datatype = "matrix"

    def tiles(self, tile_ids):
        return cooler.tiles(self.path, tile_ids)

    def info(self):
        return cooler.tileset_info(self.path)

ts = MyCustomCoolerTileset("test.mcool")
hg.view(ts.track())
```