Add functionality for detecting candiates with same start path

[sypets]

Find algorithm for suggestion of massive number of redirects with same start path - candidates for creating a regex in webserver config?

E.g. a top level page was renamend and many subpages have the same rename, e.g. study => studies. This might be a candidate for a redirect with regex in webserver config.

# start path
select REGEXP_REPLACE(source_path,'^(/[^/]*)(/.*)?$', '\\1') as p1,count(*) as c from sys_redirect group by p1 order by c;

result: (example)

| /hit                                                   |  36 |
| /lehre                                                 |  38 |
| /c3l                                                   |  50 |
| /beruf-karriere                                        |  52 |
| /test                                                  |  55 |
| /icbm                                                  |  62 |
| /materiellekultur                                      | 228 |
| /en                                                    | 490 |
+--------------------------------------------------------+-----+