[Feat] PROJ 7.0.0 released - check for adaption in (win)GRASS about grass

[metzm]

Regarding GRASS packaging, the most important new features in PROJ 7 are

• PROJ can now also access grids online using a data store in the cloud.
• The new PROJ-data package includes all grids and other resources previously tracked by the proj-datumgrid series of packages as well as some new grids.

The new PROJ-data package is with 484M quite heavy, substantially increasing the size of the standalone installer.
OTOH, not including the new PROJ-data package requires internet connection to fetch needed (parts of) grids for coordinate operations, which is inconvenient in countries with generally poor internet connection (e.g. Germany).
Therefore I opt to include the new PROJ-data package in the GRASS standalone installer.

[rs-aesi]

If the main concern is the size of pre-built Windows packages how about adjusting GRASS to use proj-7.x so that those of us running linux (perhaps macos, too) can build from source repo pulls? That makes it available for those of us who build from source while the package inclusion issue is decided.

[neteler]

@metzm just to be sure: are further changes needed in GRASS GIS to support PROJ 7.x or is that already supported?