Allow Large font size in dali

- This is done by allowing larger Atlas size, but make restriction for max 1024 size
- Padding will be handled when calculating the new atlas size
- If Max Atlas is not enough, we will fall back to default old behavior.
- This will service rendering font size even larger 500pt which services almost all users needs

Change-Id: Ib05abbc0eced6f440451b4ecf8cc8cc4640c09c8