Make sidebar specs compatible w/ BootstrapVue 2

What does this MR do?

This MR lays the groundwork for the BootstrapVue upgrade that will be done in this MR: !18913 (merged)

Due to some changes in the BTooltip and BPopover components, some tests started failing after the upgrade. Those tests need to be updated accordingly:

• sync needs to be set to false
• attachToDocument must be true

This MR focuses on upgrading the tests located in ee/spec/frontend/analytics/cycle_analytics/.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• [-] Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers