MongoDB参数解析适配问题

在使用DataX这个工具时发现针对于Java代码MongoDB建立连接时只做了简单的用户名密码解析但是携带的一些其它参数并未进行配置，例如: readPreference=secondaryPreferred&readPreferenceTags=role-cmgo:readonly-group 这些参数并未被适配

DataX MongoDBReader地址： https://github.com/alibaba/DataX/blob/master/mongodbreader/src/main/java/com/alibaba/datax/plugin/reader/mongodbreader/MongoDBReader.java

Start with mongodbreader/src/main/java/com/alibaba/datax/plugin/reader/mongodbreader/MongoDBReader.java and inspect how MongoDB connection parameters are parsed beyond the username and password. Verify how readPreference and readPreferenceTags are represented in the connection configuration; the work is done when these parameters are adapted and honored when establishing the MongoDB connection.

Written by the indexing model from the issue text.