Legend controls: second pass

### User Story Description

The MVP list contained the legend panel. That panel for the MVP had minimal functionality. New functionalities need to be added, in particular:

- control orientation of the legend (horizontal / vertical)
- color palette (select from a list of palettes. Note: usually tools show both the name and a schema of the palette)
- control number of palette levels. You can control the number of levels, value at each level and exact color
- type of interpolation (linear vs log) between palette levels
- color to use for undefined value. The user should set from the color wheel or RGB
- pick the interpolation type for the palette: continuous, banded, constant

### Acceptance Criteria

Launch a VISOR session. Color one part by a variable. In the legends panel, all the new functionalities are available and work.

Save a state file. Launch a new VISOR session. Load the state file. Verify that all the legend advanced options are stored correctly.

### Additional Links

_No response_

### Requires new or update to third party ? If "yes" add the name(s) and the version(s) of the Third Party Software.

No

### Name and Version for Third Parties

_No response_

Inicie uma sessão do VISOR e inspecione primeiro o painel de legendas existente e o fluxo de trabalho do arquivo de estado. A implementação das opções solicitadas de orientação, paleta, níveis, interpolação, cor para valores indefinidos e persistência estará concluída quando elas funcionarem para uma variável colorida e forem recarregadas corretamente de um arquivo de estado salvo.

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