[EPIC] Refactor Java and Python client API for better user experience

[shaofengshi]

Describe the proposal

The current Java client API is not user-friendly in some aspects; For example, the function that asking a Table's NameIdentifier parameter must be a fully-qualified name (with metalake name, catalog name, together with schema name and table name):

` Catalog catalog = metalake.loadCatalog(catalogName); TableCatalog tableCatalog = catalog.asTableCatalog();

NameIdentifier id = NameIdentifier.of(metalakeName, catalogName, schemaName, tableName);

Table t = tableCatalog.loadTable(id) `

Actually this is not necessary. There are also other issues, create this epic as an umbrella for such refactoring.

Task list

• 3629

• 3627

• 3698

• 3699

• 3700

• 3701

• 3702

• 3731

• 3732

[shaofengshi]

As all dev works are finished, close this issue.