Update getGamepads to include steps for copying gamepads

[nondebug]

Closes #???

The following tasks have been completed:

• Modified Web platform tests (link to pull request)

Implementation commitment:

• WebKit (https://bugs.webkit.org/show_bug.cgi?id=)
• Chromium (https://bugs.chromium.org/p/chromium/issues/detail?id=)
• Gecko (https://bugzilla.mozilla.org/show_bug.cgi?id=)

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Preview | Diff

[marcoscaceres]

This is an improvement, but I don't think this is exactly right... I think we should use #136 here..

I think what we actually want is:

• The model says there is a conceptual gamepads 🎮🎮🎮 representing real (or conceptual) things.
• When .getGamepads() is called, we go to the model and "snapshot" each conceptual gamepad (i.e., make the lists, copy stuff from the conceptual ones).
• return the result.

Right now, this reads like we are recycling what is normally returned by .getGamepads().

I'm approving, but let's move to using the model.