klp-form-select creates dropdown within scrollable container when truncateOptions is true

[janwytze]

When using klp-form-select with [truncateOptions]="true" in a scrollable container, the dropdown menu opened is contained within the scrollable container, causing part of the dropdown to be hidden. When doing this the dropdownPosition input is also not working anymore, a `[dropdownPosition]="'top'" still results in the dropdown being opened to the bottom.