[FLINK-37827][table] Fix use SHOW CREATE TABLE for MATERIALIZED_TABLE

[yanghuaiGit]

What is the purpose of the change

execute show create table for Materialized Table successful.

Brief change log

Verifying this change

1. create a MATERIALIZED TABLE t1;
2. execute show create table t1;

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• de47319 Azure: FAILURE

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• @flinkbot run azure re-run the last Azure build

[yanghuaiGit]

error info:
[ERROR] Could not execute SQL statement. Reason:
java.lang.ClassCastException: class org.apache.flink.table.catalog.ResolvedCatalogMaterializedTable cannot be cast to class org.apache.flink.table.catalog.ResolvedCatalogTable (org.apache.flink.table.catalog.ResolvedCatalogMaterializedTable and org.apache.flink.table.catalog.ResolvedCatalogTable are in unnamed module of loader 'app')