Add legacy skin and cape routes, improve error handling

Introduces legacy routes for Minecraft skins and capes to support older endpoints. Enhances error handling in sessionsRepository for missing skins/capes, adds getActiveSkin and getActiveCape to sessionsService, and improves error logging in server.js.

routes/legacy/skins/[username].js

@@ -0,0 +1,10 @@
+const express = require("express")
+const router = express.Router({ mergeParams: true })
+const sessionsService = require("../../../services/sessionsService")
+
+router.get("", async (req, res) => {
+    const cape = await sessionsService.getActiveSkin({ username: req.params.username.replace(".png", "") })
+    return res.redirect(`/textures${cape.data.url}`)
+})
+
+module.exports = router