Reversions and fixes to changes since 2.3.0.
Subdbs may not contain RIs, so we don't need /netdb tabs for them.
Partially fixes Gitlab #465.

- Remove subdb RI tabs on /netdb
- HTML fixes on subdb LS tab
- Skip subdb LS tab if no clients
- We don't need both Hash and boolean args on renderLeaseSetHTML(), just use hash != null
- Rename/cleanup/restore tagged strings, don't tag strings only visible in advanced config