Add wc-api and "Fresh Data"

[coderkevin]

This adds a wc-api module as a @wordpress/data generic store, which is based on Fresh Data

Note: This PR contains a workaround that will no longer be necessary after the following Gutenberg PR is merged: WordPress/gutenberg#11460

This leverages the general purpose fresh-data framework to create a woocommerce-specific api implementation. The first use of this is in the orders fetching for the orders table in the analytics report. The goal was to have minimal changes to the application code but still gain the advantages of sharing data across components and automatic re-fetching of data.

Detailed test instructions:

1. npm install
2. npm start
3. Visit http://localhost/wp-admin/admin.php?page=wc-admin#/analytics/orders and ensure that the orders table populates properly at the bottom.
4. Create a new order, and it should show up in the table automatically within 5 minutes.

For additional debugging information, type localStorage.setItem( 'debug', 'fresh-data:*' ); to see the updating and scheduling of data fetches.

[allendav]

Maybe as part of this, maybe separate - it would be nice to have an example where we use fresh data to detect that a new instance of a resource is available (e.g. a new order) and fetch it (e.g. to auto update a table bound to orders.)

Create a new order, and it should show up in the table [analytics - orders] automatically within 5 minutes.

Or maybe this already works without user intervention?

[allendav]

I'll take another crack at running this today, but in the meantime I wanted to get these pending comments posted.

[psealock]

hey @coderkevin, on a fresh clone of fresh-data, I npm install and get the following error on npm run build:

lerna ERR! npm run build stderr:
events.js:167
      throw er; // Unhandled 'error' event
      ^

Error: spawn babel ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:229:19)
    at onErrorNT (internal/child_process.js:406:16)
    at process._tickCallback (internal/process/next_tick.js:63:19)
    at Function.Module.runMain (internal/modules/cjs/loader.js:746:11)
    at startup (internal/bootstrap/node.js:240:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:564:3)
Emitted 'error' event at:
    at Process.ChildProcess._handle.onexit (internal/child_process.js:235:12)
    at onErrorNT (internal/child_process.js:406:16)
    [... lines matching original stack trace ...]
    at bootstrapNodeJSCore (internal/bootstrap/node.js:564:3)

are some modules missing from devDependencies?

[coderkevin]

This PR uses the updated fresh-data version and has a workaround for @wordpress/data.
It no longer needs either of those dependencies to be built to test. I've revised the testing instructions and it's ready for review again. Thanks!

[justinshreve]

This is building and testing well for me. I added a new order in another tab and it showed up pretty quickly. Nice work 👍

[timmyc]

Super happy to see this land @coderkevin - way to push it through!

[coderkevin]

Thanks! Now the rest of the work can begin. 😄