[Enhancement] [dolphinscheduler-api] Add Unit Test for UiPluginController

[ShuoTiann]

Search before asking

• I had searched in the issues and found no similar issues.

What happened

There is no Unit test for UiPluginController

What you expected to happen

Add Unit Test for UiPluginController and UT coverage is 100%

How to reproduce

Run Unit Test with Coverage

Anything else

No response

Version

dev

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

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