Refactor: Organize src/lib into subdirectories and move files accordingly.

src/lib/app_components/analytics.svelte

@@ -0,0 +1,27 @@
+<script lang="ts">
+export let log_lvl: number = 0;
+
+export let site_google_tracking_id: string = '';
+if (log_lvl) {
+    console.log(`AE Analytics: site_google_tracking_id = `, site_google_tracking_id);
+}
+
+if (typeof window !== 'undefined') {
+    window.dataLayer = window.dataLayer || [];
+    window.gtag = function gtag(): void {
+        window.dataLayer.push(arguments);
+    };
+    window.gtag('js', new Date());
+    window.gtag('config', site_google_tracking_id);
+    if (log_lvl) {
+        console.log(`AE Analytics: Google Analytics Tracking ID = `, site_google_tracking_id);
+    }
+}
+</script>
+
+<svelte:head>
+<script
+    async
+    src="https://www.googletagmanager.com/gtag/js?id={site_google_tracking_id}">
+</script>
+</svelte:head>