[index patterns] break index patterns out of data plugin into its own plugin

[mattkime]

The data plugin is too big. Lets break out the index pattern code into its own plugin.

Parent issue - #84788

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)

[Dosant]

@mattkime, have you already briefly looked at circular dependencies here and how would we resolve it?
I assume we would want to try making data dependant on index patterns and not another way around?
Also then likely field formatters registry will move together from data into index patterns and maybe even separately, where index patterns depend on field formatters?

[mattkime]

I assume we would want to try making data dependant on index patterns and not another way around?

Yes, although I'm not 100% certain how this would work out. It would be good for the data plugin to expose the index pattern plugin for backwards compatibility but past that I would try to reduce dependencies between the two.

Also then likely field formatters registry will move together from data into index patterns and maybe even separately, where index patterns depend on field formatters?

I'd try to leave field formatters alone, but I need to start on the work to really know.

[mattkime]

closed by #113497