Draft attempt to create a new grid

This a new way to make a grid... we need to test and carefully review, but I think it's more robust than the previous method.

Key points:

It uses an exact 3200x3200 10 m resolution in epsg:3832
The GeoJSON stores the coords in lat/lon, so it's easy to view, but also includes the BBOX in min_x, min_y, max_x, max_y
There's a different tile_id now, it's an x,y tile index that should stay constant between products
It's possible to get the grid extents from the definition, i.e., something like:

from odc.geo import XY
from odc.geo.gridspec import GridSpec

pacific_epsg = "EPSG:3832"
pacific_gridspec = GridSpec(crs=pacific_epsg, tile_shape=(3200,3200), resolution=30, origin=XY(-3000000, -4000000))
pacific_gridspec.tile_geobox((63,21))

digitalearthpacific / dep-grid

Draft attempt to create a new grid #3