[Lens] Allow color mapping for new metric non number fields

[stratoula]

Describe the feature:

When this is merged #137756 the users won't be able to color the tiles that have non numeric metrics. There are use cases that this would be really helpful (for example statuses use cases). We could support this by allowing the new color mapping functionality for these fields.

So in the example below I can say that I want US to be mapped with colorA, CN with colorB etc

[elasticmachine]

Pinging @elastic/kibana-visualizations (Team:Visualizations)

[nickofthyme]

users won't be able to color the tiles that have non numeric metrics

We should check for this and disable the dynamic coloring option.

[mbondyra]

Let's also add the same functionality for datatable.