pick #40891
This PR makes the following changes to the uppercase and lowercase
mapping of JdbcCatalog
1. The identifierMapping is managed by JdbcExternalCatalog instead of
JdbcClient to better control its lifecycle
2. The identifierMapping no longer loads remoteName alone, but Catalog
controls the loading uniformly
3. The identifierMapping will be loaded when each FE performs
makeSureInitialized() to ensure that each FE has a mapping
4. The initialization of mapping will only be performed once in
makeSureInitialized(), which means that even if you use metaCache, if
your source data is updated when identifierMapping is enabled, you must
refresh the catalog to query normally.
5. The identifierMapping is only responsible for the properties of the
Catalog and is no longer affected by the fe config, simplifying the
processing logic
6. If lower_case_mete_names is false and meta_names_mapping is empty in
the catalog properties, the identifierMapping will no longer take
effect, further enhancing the stability of the default settings
7. The JdbcClient is no longer closed during onRefreshCache, reducing
the repeated creation of resources, improving reuse, and reducing the
leakage of some global shared threads
3eda77b3d9