fix(app): set user-select for iOS contenteditable

[CFT-Chris]

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?

contenteditable in iOS mobile cannot be selected/edited

Issue Number: #18368

What is the new behavior?

Set user-select: text specifically for ios [contenteditable] to override app.scss rule html.plt-mobile ion-app => user-select: none. Safari's webkit implementation of user-select affects any contenteditable children, rendering them unselectable/uneditable, so this fix ensures the behavior is consistent with Chrome, FireFox, etc. and that contenteditables are selectable/editable despite the rest of the children of <ion-app> being unselectable.

Does this introduce a breaking change?

• Yes
• No

[liamdebeasi]

Thanks for the PR! I am going to close this in favor of #22404. I needed to make a few changes, but did not have access to your branch. I will give you co-author credit when I merge.

[CFT-Chris]

Sounds good. Thanks!