infoAsJSON() calculates stats

[mdsumner]

I'm just posting this as a note, I intend to explore it and make suggestions and PR.

Don't run this, it runs with -stats which is undersirable for very large sources and will take a long time.

#dsn <- "/vsicurl/https://gebco2023.s3.valeria.science/gebco_2023_land_cog.tif"
#info <- new(GDALRaster, dsn)$infoAsJSON()