implement use case for sending information to contacts

[ChengShi-1]

What this PR does / why we need it:

Implement the use case allowing users to send feedback to contacts of collection or dataset.

The use case should:

• send the information contacts
• receive back from the api with details as well

Which issue(s) this PR closes:

• Closes Implement use case for sending information to contacts #231

Related Dataverse PRs:

• Depends on #

Special notes for your reviewer:

• The contact function exists in both collection & dataset, so I create the folder outside of collection though we aim to implementing "Contact" button for collection for Q4 now.
• It allows the users that didn't log in to send information as well, so no permission restriction applies.

Suggestions on how to test this:

visually inspect and run tests on it

Is there a release notes update needed for this change?:

Additional documentation:

[GPortas]

The design, layering, and approach are correct, but we should use a different API endpoint for the reasons I mentioned in one of my comments. If there isn't an alternative endpoint in the API, we will need to implement one.

[GPortas]

Typically, we add the phrase 'See use case definition.' right below the code. Please take a look at other examples. Additionally, it would be helpful to provide a high-level description of the DTO or at least mention the type of identifier (targetId) it handles (numeric database identifier vs persistent identifiers). I assume it uses the latter, since it is numeric and is the common one for all DV objects, but it would be good to clarify.

On the other hand, the syntax in the block is incorrect. You need to first create an instance of the test DTO and then pass it as a parameter. (contact: ContactDTO) is how the parameter is defined in the method, not how it is invoked.

[GPortas]

I don't think we should use this API endpoint. It's an endpoint under the 'admin' basepath. These calls are restricted to administrators only, and AFAIK, they are limited to calls within the same host (they would fail if the consumer and the backend are not on the same host). Additionally, the call returns data that could be sensitive, such as the recipient's email address. Also, please take a look at the related comment in the endpoint definition https://github.com/IQSS/dataverse/blob/develop/src/main/java/edu/harvard/iq/dataverse/api/FeedbackApi.java#L33.