Update get_order_from_intent to use charges->data

[joshtwc]

Fixes #

Changes proposed in this Pull Request:

Webhook data for charges has key data, this change just checks if $charges is array then gets the data from the sub-key 'data' instead.

If the webhook changes to have charges as neither an object (with key data) or an array of charges, it may throw an error.

Testing instructions

Forward webhooks to your site, then complete a payment with the gateway. When payment_intent.succeeded webhook sends, it should not give a fatal error.

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• Covered with tests (or have a good reason not to test in description ☝️)
• Added changelog entry in both changelog.txt and readme.txt (or does not apply)
• Tested on mobile (or does not apply)

Post merge

• Added testing instructions to the Release Testing Instructions wiki page (or does not apply)
• Added the needs docs label (or does not apply)
• Included this PR in the Release Thread scope (or does not apply)