Data: Use consistent, accurate naming for store keys

[aduth]

Previously:

• Packages: Add package babel-plugin-transform-with-select #13177
• Refactor to remove usage of post related effects in packages/editor. #13716 (comment)

There are currently at least four naming conventions to refer to the namespace assigned to a registered store.

1. "reducer key"

   • gutenberg/packages/data/src/registry.js

     Line 146 in ede3258

     registry.registerStore = ( reducerKey, options ) => {

2. "module key"

   • gutenberg/packages/editor/src/store/index.js

     Line 18 in ede3258

     const MODULE_KEY = 'core/editor';

3. "store key"

   • gutenberg/packages/editor/src/store/controls.js

     Line 15 in ede3258

     export function dispatch( storeKey, actionName, ...args ) {

4. "store name"
   • https://github.com/WordPress/gutenberg/blob/ede325860ce76698d3915d045bb2e45d593f425c/packages/data/README.md#select-storename-string--object

We should seek to consolidate this to a single, consistent naming convention. While reducer key was the original naming, it is no longer strictly accurate since a store no longer needs to be implemented as Redux-based (see #10289).

My recommendation would be storeName, merely for alignment with the similarly-structured blockName naming.