Flyout: use theme default for position

Initial POC to prove if this idea is possible and how we feel about it.

* Related #51
* Closes #434

src/flyout.js

@@ -45,6 +45,14 @@ export class FlyoutElement extends LitElement {
       return;
     }
     this.config = config;
+
+    // The "position" is a value that can be defined from the dashboard.
+    // There are two main options: "Default" or a specific value.
+    // When "Default" is used, the value will be grabbed from the HTML element (e.g. explicitly set by the theme author).
+    // In case it's not defined, the value defined in the `constructor` will be used ("bottom-right")
+    this.position =
+      objectPath.get(this.config, "addons.flyout.position", null) ||
+      this.position;
   }
 
   _close() {