Check required properties when creating catalog.
To avoid some strange error when missing required properties
This PR add checks for:
hms catalog: check the validation of dfs.ha properties
jdbc catalog: check jdbc_url, driver_url, driver_class is set.
Fix NPE when init MasterCatalogExecutor
The MasterCatalogExecutor may be called by FrontendServiceImpl from BE, which does not have ConnectionContext.
Add more jdbc url param to resolve Chinese issue
add useUnicode=true&characterEncoding=utf-8 by default in jdbc catalog when connecting to MySQL
Update FAQ doc of catalog
d44c4b1300