Move right sidebar tooltips to the block element level

Previously, tooltips were either tied to icons or icon labels, but that has since been moved to be triggered by both in https://gitlab.com/gitlab-org/gitlab-ce/issues/25010.

Given the amount of refactoring in https://gitlab.com/gitlab-org/gitlab-ce/issues/25010, and the interactivity improvements in https://gitlab.com/gitlab-org/gitlab-ce/issues/44272, we want to move the tooltips to be triggered when the collapsed block is hovered on, to avoid the instance where there are two hover states: 1) hover state, and 2) hover state + tooltip.

Move tooltip triggers to the sidebar .block level. This only applies to the collapsed right sidebar.

This should be applied to all collapsible right sidebars for Issues, Merge Requests, Milestones, and Epics.