Fix MasterData scrollDocuments incorrect return type

[EduardoRodriguesF]

What is the purpose of this pull request?

Improve the clients usability for TypeScript.

What problem is this solving?

Fix broken return types for MasterData client's scrollDocuments method.

This is the return type of scrollDocuments as is today:

interface Response<T> {
    mdToken: string
    data: T
}

However, according to the function signature and reinforced by the LSP, it shows an incorrect type and causes inaccurate type errors:

interface Response<T> {
    mdToken: string
    data: {
        mdToken: string
        data: T
    }
}

This PR fixes it so that the return type shows the correct output as the first snippet.

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Requires change to documentation, which has been updated accordingly.