Dirk auto rescale elevation

problem
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Atm, clients can select a tool to auto-adjust the scale used for visualizing elevation. This tool only works when having the required base layer already selected. This (i) leads to inconsistent UX for the tools (since some tools can work independently from base layers) and (ii) we decided that we always want to auto-adjust the elevation colour scaling (when having the base layer selected).

solution
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The elevation layer should always auto-adjust it's colours.

todo
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- [x] Find function used for rescaling
- [x ] Trigger the function when required
- [ ] Eliminate icon for selecting the tool