dovecot: replace solr fts with flatcurve (xapian) (#5680)

* fts-flatcurve: inital implementation

* fts: removed solr from compose.yml

* flatcurve: added heap and proc logic to dovecot

* added logic for update.sh & generate for Flatcurve

* delete old iteration of fts-flatcurve.conf

* updated default fts.conf

* updated .gitignore to exclude fts.conf for further git updates

* Remove autogeneration of fts.conf (disable override)

* cleanup all left solr stuff

* renamed SKIP_FLATCURVE to SKIP_FTS

* cleanup leftovers solr in lang files

* moved lazy_expunge plugin only to mail_plugins

* added fts timeout value

* compose: remove dev image of dovecot

* updated japanese translation

data/web/lang/lang.nb-no.json

@@ -328,12 +328,10 @@
         "update_available": "En oppdatering er tilgjengelig",
         "service": "Tjeneste",
         "show_ip": "Vis offentlig IP",
-        "solr_dead": "Solr starter, er deaktivert eller døde",
         "memory": "Minne",
         "online_users": "Tilkoblede brukere",
         "restart_container": "Omstart",
         "size": "Størrelse",
-        "solr_status": "Solr-status",
         "started_at": "Startet ved",
         "started_on": "Startet den",
         "static_logs": "Statiske logger",