Add eslint rule to support breaking up packages

[spalger]

Adds a new ESLint rule to assist in breaking up packages. This is a process we expect to encourage folks use quite often, so I wanted to make it easier to handle as well as lessen the cost on contributors who already know where to import specific things from. This rule accepts a single config array in the following shape:

'@kbn/imports/exports_moved_packages': ['error', [
  {
    fromPackage: '@kbn/kitchen-sink',
    toPackage: '@kbn/spatula',
    exportNames: [
      'Spatula',
      'isSpatula'
    ]
  }
]]

This config will find any import of @kbn/kitchen-sink which specifically names either the Spatula or isSpatula export name, remove those exports (and potentially the entire import statement) and move them to a new import for @kbn/kitchen-sink. The rule assumes that toPackage is a new package so there's no reason to support adding the export to another existing import in the file. This is an opportunity for enhancement in the future if we need it.

---

Originally included this in #130464 but wanted to have a specific point to reference this new rule in the future.

[elasticmachine]

Pinging @elastic/kibana-operations (Team:Operations)

[mistic]

good idea, LGTM

[kibana-ci]

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