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/data/test440

@@ -39,7 +39,7 @@ this.hsts.example "99991001 04:47:41"
 </file>
 
 <name>
-HSTS with trailing-dot host name in URL but none in hsts file
+HSTS with trailing-dot hostname in URL but none in hsts file
 </name>
 <command>
 -x http://%HOSTIP:%HTTPPORT http://this.hsts.example./%TESTNUMBER --hsts %LOGDIR/input%TESTNUMBER -w '%{url_effective}\n'