Adds EPSG:7855 to known projections.

[na9da]

What this PR does

Adds EPSG:7855 to known projections.
This should fix ideal zoom for some layers.

Test me

Check ideal zoom before and after

Checklist

• There are unit tests to verify my changes are correct or unit tests aren't applicable (if so, write quick reason why unit tests don't exist)
• I've updated relevant documentation in doc/.
• I've updated CHANGES.md with what I changed.
• I've provided instructions in the PR description on how to test this PR.

[nf-s]

LGTM!

I can't remember much about this stuff, but is there a reason why some use of Reproject uses the terriajs Proj4Definitions instead of the terriajs-server proj4lookup service?

For example - in GeoJsonMixin the CRS needs to be in the proj4lookup service in order to reproject features

terriajs/lib/ModelMixins/GeojsonMixin.ts

Lines 1436 to 1458 in ed7c97f

	const needsReprojection = proj4ServiceBaseUrl
	? await Reproject.checkProjection(proj4ServiceBaseUrl, code)
	: false;
	if (needsReprojection) {
	try {
	filterValue(geoJson, "coordinates", function (obj, prop) {
	obj[prop] = filterArray(obj[prop], function (pts) {
	if (pts.length === 0) return [];
	return reprojectPointList(pts, code);
	});
	});
	return geoJson;
	} catch (e) {
	throw TerriaError.from(e, "Failed to reproject geoJSON");
	}
	} else {
	throw new DeveloperError(
	"The crs code for this datasource is unsupported."
	);
	}
	}

It might be worth adding EPSG:7855 to terriajs-server too

Also, this ties into the general issues with GDA2020 and GDA94 that we haven't resolved - in that the transformation from GDA2020 to WGS84, and GDA94 to WGS84 is null - but transformation from GDA94 to GDA2020 is not null.

But that is definitely for another day 🙂

[na9da]

Good observations @nf-s.

I think the Proj4Definitions is a carry over from v7. It is possible that the Reproject module was added later. We could look at switching to Reproject everywhere in code. In this case though, it might involve an async step to call Reproject.checkProjection so that a projection not available locally gets imported from the server.

Also I think, the Reproject API could be rewritten as reproject and reprojectAsync or something to avoid a checkProjection step. We could even split the projection code into a new package shared between the server and client. I feel it is best done as part of some other bigger refactoring work.

[na9da]

@nf-s terriajs-server change is here - TerriaJS/terriajs-server#150