[Web Console] Datasource page support search datasource by keyword

[fectrain]

Fixes #16370 .

Description

This PR has:

• been self-reviewed.
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[vogievetsky]

This looks really cool, thank you for the change. Added some style comments, also you should run script/licenses (from the web-console directory) to update the license list since you added a package. Do these changes + resolve conflicts and it is good to go IMO

[fectrain]

@vogievetsky Thank you so much for helping on this, I have updated the code as recommended.
BTW, the one failing check seems to be introduced by another merge, and should be able to fix by this #16469