Update WebExtensionTransformer.js resolve side_panel.defaul_path

[atl-jlandaverde]

Chrome's config for side panels uses side_panel.config instead of sidebar_action.default_panel.

https://developer.chrome.com/docs/extensions/reference/sidePanel/#use-cases

↪️ Pull Request

Chrome uses a different property to configure side panels. It uses side_panel.default_path instead of sidebar_action.default_panel. As a result we can't configure a side panel for a chrome extension

💻 Examples

In a manifest.json use the following configuration for a side panel.

{
  "name": "My side panel extension",
  ...
  "side_panel": {
    "default_path": "sidepanel.html"
  }
  ...
}

🚨 Test instructions

Configure you manifest.json for to use a side panel. Check the bundle and it should transform side_panel.default_path
{
"name": "My side panel extension",
...
"side_panel": {
"default_path": "sidepanel.html"
}
...
}

✔️ PR Todo

• Added/updated unit tests for this change - No tests for this file
• Filled out test instructions (In case there aren't any unit tests)
• [ x] Included links to related issues/PRs - Did not find any

[mischnic]

Could you add this entry to the test case here?

• https://github.com/parcel-bundler/parcel/blob/v2/packages/core/integration-tests/test/integration/webextension-mv3/manifest.json
• and then update the assertion here

  parcel/packages/core/integration-tests/test/webextension.js

  Line 104 in 6dcba36

  it('should support web extension manifest v3', async function () {

  
  (As far as I can tell, this is only in manifest version 3?)

[mischnic]

Thank you for the PR, but I just noticed that we already have a PR for this property that also has tests: #9178