set isInfoTab to true if active tab is info tab

[D-Inventor]

Prerequisites

• I have added steps to test this contribution in the description below

If there's an existing issue for this PR then this fixes
#12596

Description

I Updated the umbraco content info directive in javascript to set the isInfoTab flag to true onInit if the currently active app is the info tab.

Steps to test:

1. Log in to backoffice
2. Create new document (use a document type without any properties!)
3. Save & Publish
4. Notice that the date property is properly updated now, whereas it wouldn't be without the change.

[github-actions]

Hi there @D-Inventor, thank you for this contribution! 👍

While we wait for one of the Core Collaborators team to have a look at your work, we wanted to let you know about that we have a checklist for some of the things we will consider during review:

• It's clear what problem this is solving, there's a connected issue or a description of what the changes do and how to test them
• The automated tests all pass (see "Checks" tab on this PR)
• The level of security for this contribution is the same or improved
• The level of performance for this contribution is the same or improved
• Avoids creating breaking changes; note that behavioral changes might also be perceived as breaking
• If this is a new feature, Umbraco HQ provided guidance on the implementation beforehand
• 💡 The contribution looks original and the contributor is presumably allowed to share it

Don't worry if you got something wrong. We like to think of a pull request as the start of a conversation, we're happy to provide guidance on improving your contribution.

If you realize that you might want to make some changes then you can do that by adding new commits to the branch you created for this work and pushing new commits. They should then automatically show up as updates to this pull request.

Thanks, from your friendly Umbraco GitHub bot 🤖 🙂

[D-Inventor]

I'm not sure why some of the checks have failed. They seem to be completely unrelated to the changes that I've proposed?

[nikolajlauridsen]

Hey @D-Inventor, just ducking in to say that I took a look at the failing tests, and there seem to have been some issue setting up the test environment, but you're very right, this has nothing to do with your PR, sorry about that 😄

And thanks for your contribution! 😄

[nathanwoulfe]

@D-Inventor looks good to me 👍

I added a commit to replace some of the legacy underscore functions with vanilla javascript, only because seeing the unnecessary library usage annoys me 😄