Completely rework registry import

vscode-windows-registry choked on WOW6432Node; replacing with node-cmd calls to reg query and caching (on my machine with 70+ server definitions it was VERY slow to run 140+ commands individually; with the caching it boils down to just 5).

Also includes usability improvements as requested in review comments.

Note: on my machine, I see data both there and in the original place I was looking, and there seems to be preference for WOW6432Node, so I let that override the other location.

Author: timleavitt

package-lock.json

@@ -41,10 +41,7 @@
   },
   "dependencies": {
     "@types/vscode": "^1.44.0",
-    "node-cmd": "^3.0.0"
-  },
-  "optionalDependencies": {
-    "vscode-windows-registry": "^1.0.2"
+    "node-cmd": "^4.0.0"
   },
   "devDependencies": {
     "@types/glob": "^7.1.1",