Store the PROJJSON representation of ogc-84 crs (#606)

In pyodide, the pyproj PROJ data directory is much smaller, and it
currently
hard-crashes on the line `pyproj.CRS("ogc:84")`. Instead, we vendor the
PROJJSON
representation of this CRS, which works in pyodide.

lonboard/_constants.py

@@ -3,7 +3,83 @@
 import pyproj
 
 EPSG_4326 = pyproj.CRS("epsg:4326")
-OGC_84 = pyproj.CRS("ogc:84")
+
+# In pyodide, the pyproj PROJ data directory is much smaller, and it currently
+# hard-crashes on the line `pyproj.CRS("ogc:84")`. Instead, we vendor the PROJJSON
+# representation of this CRS, which works in pyodide.
+OGC_84_dict = {
+    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
+    "type": "GeographicCRS",
+    "name": "WGS 84 (CRS84)",
+    "datum_ensemble": {
+        "name": "World Geodetic System 1984 ensemble",
+        "members": [
+            {
+                "name": "World Geodetic System 1984 (Transit)",
+                "id": {"authority": "EPSG", "code": 1166},
+            },
+            {
+                "name": "World Geodetic System 1984 (G730)",
+                "id": {"authority": "EPSG", "code": 1152},
+            },
+            {
+                "name": "World Geodetic System 1984 (G873)",
+                "id": {"authority": "EPSG", "code": 1153},
+            },
+            {
+                "name": "World Geodetic System 1984 (G1150)",
+                "id": {"authority": "EPSG", "code": 1154},
+            },
+            {
+                "name": "World Geodetic System 1984 (G1674)",
+                "id": {"authority": "EPSG", "code": 1155},
+            },
+            {
+                "name": "World Geodetic System 1984 (G1762)",
+                "id": {"authority": "EPSG", "code": 1156},
+            },
+            {
+                "name": "World Geodetic System 1984 (G2139)",
+                "id": {"authority": "EPSG", "code": 1309},
+            },
+        ],
+        "ellipsoid": {
+            "name": "WGS 84",
+            "semi_major_axis": 6378137,
+            "inverse_flattening": 298.257223563,
+        },
+        "accuracy": "2.0",
+        "id": {"authority": "EPSG", "code": 6326},
+    },
+    "coordinate_system": {
+        "subtype": "ellipsoidal",
+        "axis": [
+            {
+                "name": "Geodetic longitude",
+                "abbreviation": "Lon",
+                "direction": "east",
+                "unit": "degree",
+            },
+            {
+                "name": "Geodetic latitude",
+                "abbreviation": "Lat",
+                "direction": "north",
+                "unit": "degree",
+            },
+        ],
+    },
+    "scope": "Not known.",
+    "area": "World.",
+    "bbox": {
+        "south_latitude": -90,
+        "west_longitude": -180,
+        "north_latitude": 90,
+        "east_longitude": 180,
+    },
+    "id": {"authority": "OGC", "code": "CRS84"},
+}
+
+OGC_84 = pyproj.CRS.from_json_dict(OGC_84_dict)
 
 
 class EXTENSION_NAME(bytes, Enum):