UI: Fix Storage tab content overlap

[Revanth14]

closes: #68754

The details-panel collapse control is absolutely positioned over the left edge of the tab content, so on the Storage tab it covered the start of the Task State Store and XCom Key column. This adds start spacing to the Storage sub-tabs so
their content no longer sits under that control.

The spacing is applied only to the Storage sub-tabs, so Logs, Code, Details, and other task tabs keep their existing layout.

Before:

After:

[jroachgolf84]

LGTM

[pierrejeambrun]

This issue isn't specific to the 'storage' tab. It's basically any 'right detail' panel not having enough spacing left that will be impacted.

For instance here is the task tab:

To fix this everywhere, I would argue for making the button much 'smaller' horizontally, and maybe expand the button back to the current shape and form when hovering the >.

Or any other design update that will make this button disappear or be somehow smaller. (move it at the top of the vertical separator)

The other alternative is simply to pad left all tabs, to make sure they don't overlap but this will be cumbersome. Some tabs already have enough padding, and don't need extra, some others do etc....

[pierrejeambrun]

Thanks for the PR.

Not the right approach, that's fixing only the storage tab, while the bug can appear on any right pane tabs.

Closing in favor of #69240.