[Improve][Docs] Refactor MySQL-CDC docs (#5302)

* [Improve][Docs] Refactor MySQL-CDC docs

* Update MySqlTypeUtils.java

* Update MySQL-CDC.md

Author: hailin0

docs/en/connector-v2/formats/cdc-compatible-debezium-json.md

@@ -19,7 +19,6 @@ source {
   MySQL-CDC {
     result_table_name = "table1"
 
-    hostname = localhost
     base-url="jdbc:mysql://localhost:3306/test"
     "startup.mode"=INITIAL
     catalog {