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.zh-cn.json

@@ -505,7 +505,6 @@
         "external_logs": "外部日志",
         "history_all_servers": "历史 (所有服务器)",
         "in_memory_logs": "内存日志",
-        "jvm_memory_solr": "JVM 内存使用",
         "last_modified": "最后修改",
         "log_info": "<p>Mailcow 的<b>内存日志</b>储存于 Redis 列表中，并且每分钟自动降低到 LOG_LINES (%d) 以减少错误。\r\n  <br>内存日志不是为了持久化储存的，所有使用内存日志的应用同时也会写入日志到 Docker 的守护进程的默认日志驱动中。\r\n  <br>内存日志应该用于分析 (Debug) 容器中不明显的问题。</p>\r\n  <p><b>外部日志</b>通过相应应用提供的 API 收集。</p>\r\n  <p><b>静态日志</b>大多数为不写入日志到 Docker ，但仍然需要被持久化的活动日志 (API 日志外的)。</p>",
         "login_time": "时间",
@@ -514,8 +513,6 @@
         "restart_container": "重启",
         "service": "服务",
         "size": "大小",
-        "solr_dead": "Solr 在启动中、已关闭或已停止。",
-        "solr_status": "Solr 状态",
         "started_at": "开始于",
         "started_on": "启动于",
         "static_logs": "静态日志",