This patch fixes the following issues when the Material TextArea is
attached to a Flickable:
- Floating placeholder text scrolls with the Flickable.
- When text is cleared without the control having focus:
- Floating placeholder text is positioned incorrectly.
- The floating text background outline gap is still open.
- The background outline color is incorrect when the control has focus
(used primaryTextColor instead of accentColor).
Pick-to: 6.5
Task-number: QTBUG-112650
Change-Id: Icfa3517e4abcb1209ea2291dabdec225011f19ef
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>