Alternative themes

[asnyv]

Some users request themes with an "Equinor look" but with slightly different default wishes than what we have. Not sure to which extend we should offer many Equinor themes, but we could at least discuss it? Some questions are:

• Grid lines in plots
• Not to use SI postfixes, but rather just use exponentials (so change exponentformat): https://github.com/equinor/webviz-config-equinor/blob/57d78f21432d2e8efc8a21edbf90d894115ddbb5/webviz_config_equinor/__init__.py#L39-L40

This will of course only be valid for plotly plots were we use the plotly theming, but might make some users happy with relatively low effort :)

[asnyv]

suggestion: Option to change some plotly settings in yaml-config.