fix: Handle hudi table reads when databaseName is not set during initTable

[vinishjail97]

Describe the issue this Pull Request addresses

Fixes an issue where Hudi tables fail to load with IllegalArgumentException: "is not a Hudi table" when hoodie.database.name is not set in the table config during initialization. This occurs because when both table.identifier.database and getCurrentDatabase are null/empty during table initialization, the database name is not defaulted to "default", causing inconsistent behavior between table creation and querying.

Summary and Changelog

Tables initialized without an explicit database name now correctly default to "default" database, preventing subsequent read failures.

Impact

No public API changes. This is an internal fix to ensure consistent behavior.

Risk Level

Low

Documentation Update

None.

Contributor's checklist

• Read through contributor's guide
• Enough context is provided in the sections above
• Adequate tests were added if applicable

[vinishjail97]

Rebased with latest master.

[hudi-bot]

CI report:

• f3a5d36 Azure: FAILURE

Bot commands

@hudi-bot supports the following commands:

• @hudi-bot run azure re-run the last Azure build

[vinishjail97]

Azure CI is flaky.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-jar-plugin:3.1.2:jar (default-jar) on project hudi-kafka-connect: Error assembling JAR: Problem creating jar: Execution exception: Java heap space -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
[ERROR] 
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <args> -rf :hudi-kafka-connect

[danny0405]

Azure CI retriggered.

[danny0405]

Azure CI passed: https://dev.azure.com/apachehudi/hudi-oss-ci/_build/results?buildId=10820&view=results