FIX Argument order of insertBefore method

[satrun77]

Description

When applying workflow to a page. There is an error related to an incorrect argument for insertBefore

[Emergency] Uncaught TypeError: SilverStripe\Forms\FieldList::insertBefore(): Argument #2 ($item) must be of type SilverStripe\Forms\FormField, string given, called in /Users/mo/Sites/cms/vendor/silverstripe/framework/src/Forms/CompositeField.php on line 349

Manual testing steps

• Create a new workflow and select a default template
• Fill in all required fields for workflow and save
• Create another workflow
• Go to Pages
• Edit a page
• Go to settings
• Select the workflow you have created in Applied Workflow
• Select the second workflow in Additional Workflows
• Save and go back to the Content tab
• There is an error about the incorrect argument

Issues

• Incorrect argument order in WorkflowApplicable extension #514

Pull request checklist

• The target branch is correct
  • See picking the right version
• All commits are relevant to the purpose of the PR (e.g. no debug statements, unrelated refactoring, or arbitrary linting)
  • Small amounts of additional linting are usually okay, but if it makes it hard to concentrate on the relevant changes, ask for the unrelated changes to be reverted, and submitted as a separate PR.
• The commit messages follow our commit message guidelines
• The PR follows our contribution guidelines
• Code changes follow our coding conventions
• This change is covered with tests (or tests aren't necessary for this change)
• Any relevant User Help/Developer documentation is updated; for impactful changes, information is added to the changelog for the intended release
• CI is green

[GuySartorelli]

Thanks for your patience - works well locally now that I can reproduce.

[GuySartorelli]

As with the other PR you did, if you want to retarget this to the 6.1 branch it can be released immediately - but otherwise I'm happy to merge as-is and it'll be released in April

[GuySartorelli]

LGTM