[ISSUE-4323][Bug] Fix flink conf path recovery

[hutiefang76]

What changes were proposed in this pull request

Issue Number: close #4323

Related #4316.

This pull request fixes the Flink Conf view path when t_flink_env.flink_conf contains the Flink home path instead of the compressed config content. In that case DeflaterUtils.unzipString fails before the page can render the config.

The recovery is intentionally conservative: it only reloads the config from flinkHome when the stored value equals, or normalizes to, the configured Flink home path. Other invalid compressed values still fail as before.

Brief change log

• Reuse one Flink conf YAML resolver for convertFlinkYamlAsMap, unzipFlinkConf, and getFlinkConfig.
• Recover historical flink_conf values that were stored as the Flink home path by calling the existing doSetFlinkConf flow.
• Add FlinkEnvTest coverage for exact path recovery, trailing slash recovery, and getFlinkConfig usage.

Verifying this change

This change added tests and can be verified as follows:

• Added FlinkEnvTest to cover the recovery behavior.
• Ran JAVA_HOME=$(/usr/libexec/java_home -v 17) ./mvnw -Pfast -pl streampark-console/streampark-console-service -am -DskipTests=false -Dcheckstyle.skip=true -Dtest=FlinkEnvTest -Dsurefire.failIfNoSpecifiedTests=false test
• Ran JAVA_HOME=$(/usr/libexec/java_home -v 17) ./mvnw -pl streampark-console/streampark-console-service -DskipTests spotless:check
• Ran git diff --check and git diff --cached --check

Does this pull request potentially affect one of the following parts

• Dependencies (does it add or upgrade a dependency): no

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[hutiefang76]

Closing this PR because the linked issue was closed by the project as outdated on September 3. The branch has also diverged from current dev, so rebasing it would add noise without an active upstream request. Thanks for the review time.