implement some GEO commands, improve scan generic transformer, expose RPUSHX

lib/commands/GEOSEARCH.ts

@@ -0,0 +1,16 @@
+import { GeoSearchFrom, GeoSearchBy, GeoSearchOptions, pushGeoSearchArguments, transformReplyStringArray } from './generic-transformers';
+
+export const FIRST_KEY_INDEX = 1;
+
+export const IS_READ_ONLY = true;
+
+export function transformArguments(
+    key: string,
+    from: GeoSearchFrom,
+    by: GeoSearchBy,
+    options?: GeoSearchOptions
+): Array<string> {
+    return pushGeoSearchArguments(['GEOSEARCH'], key, from, by, options);
+}
+
+export const transformReply = transformReplyStringArray;