feat: add incident support

[patrick-stephens]

What problem does this feature solve?

I would like to enable incidents for dashboards.

How would you implement this feature?

An additional boolean flag to turn on/off on dashboards.

[wvanderdeijl]

Would be nice if this was added. Currently, every time we change any of the other properties of a dashboard the (manually) enabled incidents features gets disabled again.

[geirarne]

This. The only thing I found that was a regression when moving from click-ops to Terraform, but still.

[sorccu]

GH prematurely closed this issue but we'll have a release out soon that finally includes this. Sorry for taking so long.