fix(modal, popover): opening modal and popover now works even if overlay was added to ion-app directly

[liamdebeasi]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue Number: resolves #23728

What is the new behavior?

• Modal now opens correctly when placed directly inside of ion-app
• Shadows/backdrop opacities are correctly set for the first open modal
• This changes also fixes a "gotcha" I missed when building declarative modals. If you are creating a modal via document.createElement, then the modal is no longer automatically removed from the DOM when the modal is dismissed. Impact on this is low since most developers use modalController.

Note: I couldn't think of a better way of doing this fix without the hasController internal prop, so if you have other ideas definitely let me know!

Does this introduce a breaking change?

• Yes
• No

Other information

[averyjohnston]

Had a minor change and a question below. I couldn't think of a better way than the hasController prop either; since you can theoretically insert a modal anywhere, we can't rely on location in the DOM, and there isn't an inherent difference between modal elements of different types besides the new prop. So I think we're good there.