PR: Add the option to hide or show the weather data in the tool to visualize the water levels dynamically and improve the look of the plot

[jnsebgosselin]

Similarly to what was done in PR #205 for the GLUE predicted water levels, the goal of this PR is to add the possibility to show or hide the weather data in the tool to visualize the water levels dynamically.

Also improve the look of the plot:

• change the color of the Rain and Snow bar to match the default colors used in the hydrograph editor.
• change how the ETP is plotted by using a continuous line instead of vertical lines.

[jnsebgosselin]