Restrict SSR to paths in the sitemap

Because Angular SSR is not very efficient, after discussion with
the Google Scholar team we realized a compromise would be to only
use SSR for pages in the DSpace sitemap (and the home page).

src/environments/environment.ts

@@ -13,6 +13,7 @@ export const environment: Partial<BuildConfig> = {
     enabled: false,
     enablePerformanceProfiler: false,
     inlineCriticalCss: false,
+    paths: [ '/home', '/items/', '/entities/', '/collections/', '/communities/', '/bitstream/', '/bitstreams/', '/handle/' ],
   },
 };