Support Notification Center

Pull Request description

[x] You have reviewed the guidelines document.
[x] Labels that classify your pull request have been added.
[x] The milestone is specified and corresponds to fix version.
[x] Description references specific issue.
[x] Description contains human-readable scope of changes.
[x] Description contains brief notes about what needs to be added to the documentation.
[x] No merge conflicts, commented blocks of code, code formatting issues.
[x] Changes are backward compatible or upgrade script is provided.
[x] Similar PR is opened for PE version to simplify merge. Crosslinks between PRs added. Required for internal contributors only.

[x] Added corresponding unit and/or integration test(s). Provide written explanation in the PR description if you have failed to add tests.
[x] If new dependency was added: the dependency tree is checked for conflicts.
[x] If new service was added: the service is marked with corresponding @TbCoreComponent, @TbRuleEngineComponent, @TbTransportComponent, etc.
[x] If new REST API was added: the RestClient.java was updated, issue for Python REST client is created.
[x] If new yml property was added: make sure a description is added (above or near the property).