[NUI] Add FontSizeScale in TextStyle

[NUI] Add FontSizeScale in TextStyle

Setting FontSizeScale to UseSystemSetting in Theme,
the default font scale follows the properties of system.

- Added new argument to New(bool hasStlye)
- If true, DALi's json is no longer used in Text components
- If false, use DALi's json.

- Fixed previous incorrect bindable property structure.

- This must be sync merged with patches below.
https://review.tizen.org/gerrit/#/c/platform/core/uifw/dali-toolkit/+/284113/
https://review.tizen.org/gerrit/#/c/platform/core/uifw/dali-csharp-binder/+/284127/

Signed-off-by: Bowon Ryu <bowon.ryu@samsung.com>