[Layer] Add a visual indication when a layer is only visible from a certain zoom level

[bruhnild]

Description:
Currently, when a layer is not visible because the zoom level is too low, there is no clear indication for the user. This can cause confusion, as the user may think the layer is empty or not working.

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Requested enhancement:
Add a visual indication at the top of the map when the selected layer is only visible starting from a certain zoom level.
For example:

• A banner or message saying: “Zoom in to see this layer”
• The message should disappear once the zoom level is sufficient to display the data.

Expected benefits:

• Improve user understanding of why a layer is not displayed.
• Avoid confusion between “layer not available” and “layer hidden because of zoom level”.