Add end to end tests for the SitemapInjector

[lfoppiano]

@sebastian-nagel I've manage, not without any problems, to get an end to end test running around the SitemapInjector. However is a Draft PR and the tests are still failing, see my question below.

It should simulate the process via protocol-file and make Nutch in the condition of running the sitemapInjector on any sitemap, load them into CrawlDB and verify.

I've created two tests, one for the KPMG and one for your sitemap.xml example.
I'm having problems to understand how to assert the number of URLs, e.g. what is counted by hadoop:

2026-04-16 22:01:02,576 INFO o.a.n.c.SitemapInjector [Thread-43] Found 1474 URLs in file:/Users/lfoppiano/development/projects/cc/nutch/src/testresources/sitemaps/sitemap.example.1.xml
2026-04-16 22:01:02,588 INFO o.a.n.c.SitemapInjector [Thread-43] Injected total 4630 URLs for file:/Users/lfoppiano/development/projects/cc/nutch/src/testresources/sitemaps/sitemap.example.1.xml
2026-04-16 22:01:02,812 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:     3156  sitemap_extension_localized_link
2026-04-16 22:01:02,812 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:        1  sitemap_type_xml
2026-04-16 22:01:02,812 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:        1  sitemaps_processed
2026-04-16 22:01:02,812 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:     4630  urls_from_sitemaps_injected

2026-04-16 22:01:04,665 INFO o.a.n.c.SitemapInjector [Thread-160] Found 866 URLs in file:/Users/lfoppiano/development/projects/cc/nutch/src/testresources/sitemaps/sitemap.example.2.xml
2026-04-16 22:01:04,668 INFO o.a.n.c.SitemapInjector [Thread-160] Injected total 2598 URLs for file:/Users/lfoppiano/development/projects/cc/nutch/src/testresources/sitemaps/sitemap.example.2.xml
2026-04-16 22:01:05,357 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:     1732  sitemap_extension_localized_link
2026-04-16 22:01:05,358 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:        1  sitemap_type_xml
2026-04-16 22:01:05,358 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:        1  sitemaps_processed
2026-04-16 22:01:05,358 INFO o.a.n.c.SitemapInjector [main] SitemapInjector:     2598  urls_from_sitemaps_injected

and what is cumulated in the crawl db, when I check in

[...]
        SitemapInjector sitemapInjector = new SitemapInjector();
        sitemapInjector.setConf(conf);
        sitemapInjector.inject(crawldbPath, urlPath);

        List<String> injected = readCrawldb();

I did not find any way to count manually the expected URLs and compare them with injected.size(), but I'm surely missing something here..