Align top-right header action buttons (`RefreshButton` and `shareButton`)
to `Qt.AlignTop` across Overview, Usage & Spend, and Sessions views,
matching `ProviderHeader` alignment and preventing vertical button jumps
when switching popup tabs or when header subtitles expand.

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Co-authored-by: Lucenx9 <185146821+Lucenx9@users.noreply.github.com>