Introduce geolayer widget for specifying layers for geomap

plugins/tiddlywiki/geospatial/tests/widgets/geomap-refresh.tid

@@ -0,0 +1,58 @@
+title: $:/plugins/tiddlywiki/geospatial/tests/widgets/geomap-refresh
+description: refreshing of geomap widget
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Description
+text: Map using dynamic geolayer to represent features
++
+title: Layer
+tags: $:/tags/GeoFeature
+type: application/json
+color: red
+
+{
+	"type": "FeatureCollection",
+	"features": [
+		{
+			"type": "Feature",
+			"id": "An example geofeature feature",
+			"properties": {
+				"custom": "A custom property of this feature",
+				"color": "#ff8"
+			},
+			"geometry": {
+				"type": "Polygon",
+				"coordinates": [
+					[
+						[-90,35],
+						[-90,30],
+						[-85,30],
+						[-85,35],
+						[-90,35]
+					]
+				]
+			}
+		}
+	]
+}
++
+title: Output
+
+<$button>
+<$action-setfield $tiddler="$:/state/layer" $value="yes"/>
+Click here to enable the layer
+</$button>
+
+<$geomap
+	state=<<qualify "$:/state/demo-map">>
+>
+	<$geolayer 
+		json={{{ [{$:/state/layer}match[yes]then{Layer}else[]] }}}
+		colorFilter="[<currentTiddler>jsonget[properties],[color]else[red]]"
+	/>
+</$geomap>
++
+title: ExpectedResult
+
+<p>Winchester,Oxford,</p>

plugins/tiddlywiki/geospatial/tests/widgets/geomap.tid

@@ -0,0 +1,53 @@
+title: $:/plugins/tiddlywiki/geospatial/tests/widgets/geomap
+description: geomap widget
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Description
+text: Map using geolayer to represent features
++
+title: Layer
+tags: $:/tags/GeoFeature
+type: application/json
+color: red
+
+{
+	"type": "FeatureCollection",
+	"features": [
+		{
+			"type": "Feature",
+			"id": "An example geofeature feature",
+			"properties": {
+				"custom": "A custom property of this feature",
+				"color": "#ff8"
+			},
+			"geometry": {
+				"type": "Polygon",
+				"coordinates": [
+					[
+						[-90,35],
+						[-90,30],
+						[-85,30],
+						[-85,35],
+						[-90,35]
+					]
+				]
+			}
+		}
+	]
+}
++
+title: Output
+
+<$geomap
+	state=<<qualify "$:/state/demo-map">>
+>
+	<$geolayer 
+		json={{Layer}}
+		colorFilter="[<currentTiddler>jsonget[properties],[color]else[red]]"
+	/>
+</$geomap>
++
+title: ExpectedResult
+
+<p>Winchester,Oxford,</p>