Fix (UI): Correct Zoom Button Order

[leherkom]

Pull request

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Please describe your changes

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Reorders the buttons for the zoom adjustment such that decreasing zoom is placed on the left and increasing zoom is placed on the right.

• Describe what your code exactly does and if it affects any other part of the code in any way (especially check for breaking changes)

Swaps the order of the nodes within the ZoomAdjustment component and adjusts the corresponding CSS classes so borders render properly.

Fixes #723

[trobonox]

LGTM, thanks for helping out with the fix!