Add more layers to Map component.

This commits adds back the vessel track as well as other layers,
gives the option to load both point and line versions of the plan,
raw, and final sequences, and adds heatmaps showing positioning
error of raw and final data relative to preplots.

The implementation in this commit relies on translating the binary
sequence data into JSON (for the heatmaps) which is inefficient
but adequate as an initial proof of concept.

lib/www/client/source/package.json

@@ -7,6 +7,7 @@
     "build": "vue-cli-service build"
   },
   "dependencies": {
+    "@deck.gl/aggregation-layers": "^9.1.13",
     "@dougal/organisations": "file:../../../modules/@dougal/organisations",
     "@dougal/user": "file:../../../modules/@dougal/user",
     "@mdi/font": "^7.2.96",