Available datasets panel

[datasantana]

Create a panel that lista available datasets to be added as layers to map

• [x] Add slider activator to switch between map layers and available datasets
• [x] Add list of datasets with miniatures and description
• [x] Add button for adding selected datasets as map layer
• [ ] Slider should move automatically to map layers after adding selected layers
• [x] Add a button to remove added layers

[datasantana]

A v-window control was added to switch between map layers and available datasets (add layer):

Expansion panels were used for grouping datasets inside corresponding category. Inside each category there is a card for each dataset:

I plan to use checkboxes to indicate which datasets have been added as a new layer, showing them as checked, and the available ones as unchecked. The datasets that are already added will also be displayed as greyed-out cards.

[datasantana]

Completed redesign of layers panel. Now it shows al datasets and let user to add datasets as map layers.

When layer is added, user can remove it or see layer controls and legend.

User will be able to toggle legend entries if there are more than one.