After multiple discussions, including a recent mention in #52374, we determined that as an app architecture team convention, we should be explicitly exporting static code & types from the data/public/index.ts and data/server/index.ts.

This is important for two main reasons:

1. Prevents leaking internal APIs which are simply implementation details of the plugin.
   • Devs will need to go out of their way to expose something on the public contract... which is a good thing.
   • Allows us to use export * in the rest of the plugin with confidence that we won't be messing with the public API.
2. Creates a single file for someone to view the entire contract for a plugin's static code.
   • Helps with maintenance: when you see all of the interfaces that other plugins could be consuming in your plugin, it is easier to understand how widespread usage is.
   • Improves discoverability for devs using our plugins since they can "see" everything in one place.
   • Removes another level of indirection.

This PR takes a first step toward achieving these goals in the data plugin by doing the following:

• Removes export * from '../common', which is one area where we had a lot of mixed internal/public code, some of which was accidentally leaking into the public contract.
• Explicitly exports only the items from common which are used outside of the data plugin.
• Removes the utils namespace inside of common/es_query which was introduced in Move @kbn/es-query into data plugin - es-query folder #50182. These could lead to confusion since the utils are specifically related to es_query and are mostly internal, yet were being exported from the top-level data/public and data/index.
  • It also removes a few methods from the esQuery namespace which were only used internally
  • No release notes have been added for this change since it will land in 7.6 along with Move @kbn/es-query into data plugin - es-query folder #50182

Eventually the remaining data exports should also be cleaned up, as well as other plugins managed by the app arch team.