Replace favico.js dependency with simplified variant grown from it

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/@types/global.d.ts

@@ -24,5 +24,11 @@ declare global {
 
         // electron-only
         ipcRenderer: any;
+
+        // opera-only
+        opera: any;
+
+        // https://developer.mozilla.org/en-US/docs/Web/API/InstallTrigger
+        InstallTrigger: any;
     }
 }