Add support for sorting issues by blocking issues count in ascending order

We should add support for ascending sort by blocking issues count in issue list.

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This is a follow-up issue to the following discussion in !44389 (merged)

Jan Provaznik @jprovaznik

could you confirm if we can sort the issues in ascending order?

@euko, good point - we would need to add scope for ascending order too.

@aregnery @euko WDYT about creating a follow-up for adding ascending support and we can merge this now?