Schedule cache count update on group transfer

What does this MR do and why?

Schedules update of cache counts for nullified parent epics.

Related to #373834 (closed)

Screenshots or screen recordings

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Example below:

1. In rails console enable cache_issue_sums

   Feature.enable(:cache_issue_sums)

2. create a group with a subgroup
3. create epics both in group and subgroup and set parent epic for the epic in subgroup
4. assign an issue to the epic in the subgroup
5. check in console that total_opened_issue_count is set both for parent and subepic
6. transfer subgroup under different root group
7. check that total_opened_issue_count was updated after a minute

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.