`IssueFields.Unknowns` and `IssueFields.Names` not returned in `Issue.SearchWithContext` api

## What happened?

The fields `IssueFields.Unknowns` and `IssueFields.Names` are not being returned in `Issue.SearchWithContext` API, while its coming in the `Issue.Get` API.
We are setting `Expand: "names"` in the `SearchOptions`

## What did you expect to happen?

The fields `IssueFields.Unknowns` and `IssueFields.Names` return the information in the Search API.

## How can we reproduce it (as minimally and precisely as possible)?

```go
options := jira.SearchOptions{
StartAt: 0,
MaxResults: limit,
Expand: "names",
}

issues, res, err := client.Issue.SearchWithContext(ctx, jql, &options)
```

## Your Environment

* go-jira version (git tag or sha): 1.16.0
* Go version (`go version`): go version go1.20.3 darwin/arm64
* Jira type (cloud or on-premise): cloud
* Jira version / Api version: