DidDocumentOptions.controller field has a wrong type

[spivachuk]

The type of DidDocumentOptions.controller field does not permit a string value which is a correct one for DidDocument.controller field:

interface DidDocumentOptions {
  ...
  controller?: string[]
  ...
}

export class DidDocument {
  ...

  @IsStringOrStringArray()
  @IsOptional()
  public controller?: string | string[]
  
  ...
}

[berendsliedrecht]

Thanks for pointing it out. #1644 will fix this.