badwords: fix issues found in tests

There remain some false positives, hits in test data, and `dir` use,
around 100 issues in total.

There is no plan to enforce badwords on tests.

Also:
- badwords.txt: let a few `manpage[s]` occurrences through
  (in Perl code).

Closes #19541

tests/http/test_10_proxy.py

@@ -265,7 +265,7 @@ class TestProxy:
     @pytest.mark.skipif(condition=not Env.curl_is_debug(), reason="needs curl debug")
     @pytest.mark.skipif(condition=not Env.curl_is_verbose(), reason="needs curl verbose strings")
     def test_10_10_reuse_proxy(self, env: Env, httpd, nghttpx_fwd, tunnel):
-        # url twice via https: proxy separated with '--next', will reuse
+        # URL twice via https: proxy separated with '--next', will reuse
         if tunnel == 'h2' and not env.curl_uses_lib('nghttp2'):
             pytest.skip('only supported with nghttp2')
         if env.curl_uses_lib('mbedtls') and \