g.proj: Add JSON support

[NishantBansal2003]

ref: #4104

This pull request integrates to add JSON output support to the g.proj module. With these changes, g.proj now supports output in JSON format when invoked with the -p, -j, or -w flags.

The behaviour is as follows:

• -p flag:

  {
      "name": "Lambert Conformal Conic",
      "proj": "lcc",
      "datum": "nad83",
      "a": "6378137.0",
      "es": "0.006694380022900787",
      "lat_1": "36.16666666666666",
      "lat_2": "34.33333333333334",
      "lat_0": "33.75",
      "lon_0": "-79",
      "x_0": "609601.22",
      "y_0": "0",
      "no_defs": "defined",
      "unit": "Meter",
      "units": "Meters",
      "meters": "1"
  }

• -j flag:

  {
      "proj4": "+proj=lcc +lat_1=36.16666666666666 +lat_2=34.33333333333334 +lat_0=33.75 +lon_0=-79 +x_0=609601.22 +y_0=0 +no_defs +a=6378137 +rf=298.257222101 +towgs84=0.000,0.000,0.000 +type=crs  +to_meter=1"
  }

• -w flag:

  {
      "wkt": "PROJCRS[\"unknown\",\n    BASEGEOGCRS[\"grs80\",\n        DATUM[\"North American Datum 1983\",\n            ELLIPSOID[\"Geodetic_Reference_System_1980\",6378137,298.257222101,\n                LENGTHUNIT[\"metre\",1]],\n            ID[\"EPSG\",6269]],\n        PRIMEM[\"Greenwich\",0,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8901]]],\n    CONVERSION[\"unnamed\",\n        METHOD[\"Lambert Conic Conformal (2SP)\",\n            ID[\"EPSG\",9802]],\n        PARAMETER[\"Latitude of false origin\",33.75,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8821]],\n        PARAMETER[\"Longitude of false origin\",-79,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8822]],\n        PARAMETER[\"Latitude of 1st standard parallel\",36.1666666666667,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8823]],\n        PARAMETER[\"Latitude of 2nd standard parallel\",34.3333333333333,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8824]],\n        PARAMETER[\"Easting at false origin\",609601.22,\n            LENGTHUNIT[\"metre\",1],\n            ID[\"EPSG\",8826]],\n        PARAMETER[\"Northing at false origin\",0,\n            LENGTHUNIT[\"metre\",1],\n            ID[\"EPSG\",8827]]],\n    CS[Cartesian,2],\n        AXIS[\"easting\",east,\n            ORDER[1],\n            LENGTHUNIT[\"metre\",1,\n                ID[\"EPSG\",9001]]],\n        AXIS[\"northing\",north,\n            ORDER[2],\n            LENGTHUNIT[\"metre\",1,\n                ID[\"EPSG\",9001]]]]"
  }

NOTES: The code changes are largely based on the modifications introduced in #4104 with additional tweaks to address all review comments.

[NishantBansal2003]

Could we re-run this CI? The error does not seem to be related.

Errors in:
/d/a/grass/grass/lib/db/dbmi_driver
/d/a/grass/grass/db/drivers/sqlite
/d/a/grass/grass/db/drivers/postgres
/d/a/grass/grass/db/drivers/dbf
/d/a/grass/grass/db/drivers/ogr
/d/a/grass/grass/db/drivers/odbc