Boards swimlanes - issue detail not closed when epic sidebar opened

Context

The following discussion from !38527 (merged) should be addressed:

• @pslaughter started a discussion:

  issue (non-blocking): It looks like we never close out the detailIssue sidebar when the "Group by" is activated.

  

  This leads to the swimlanes sidebar being covered until the detailIssue one is manually closed.