Problem description: If a resizable input field is a part of a form in a popup window (like in media type test), it is possible to horizontally resize this input field outside of the popup window, so that it becomes impossible to resize it again.

Steps to reproduce:

1. Navigate to Administration => Media types
2. Press "Test" button next to any Email or SMS media type
3. In the opened popup window attempt to resize the field "Message" as far to the right side as possible

Result: It is possible to resize field message so far to the right that it becomes wider that the popup window it is located in and a part of this field is not available anymore, including the corner that needs to be dragged for resizing.

Expected: It should not be possible to resize a field so much that it doesn't fit in the window (popup) its located in.

Example: