[ACR-1754] Add new APIs for camera settings

[ACR-1754] Add new APIs for camera settings

- New enums in camera_attr_exposure_mode_e
 : CAMERA_ATTR_EXPOSURE_MODE_SHUTTER_PRIORITY
 : CAMERA_ATTR_EXPOSURE_MODE_APERTURE_PRIORITY
- New functions
 : int camera_attr_set_gain(camera_h camera, int level);
 : int camera_attr_get_gain(camera_h camera, int *level);
 : int camera_attr_get_gain_range(camera_h camera, int *min, int *max);
 : int camera_attr_get_gain_step(camera_h camera, int *step);
 : int camera_attr_set_whitebalance_temperature(camera_h camera, int temperature);
 : int camera_attr_get_whitebalance_temperature(camera_h camera, int *temperature);
 : int camera_attr_get_whitebalance_temperature_range(camera_h camera, int *min, int *max);
 : int camera_attr_get_whitebalance_temperature_step(camera_h camera, int *step);
 : int camera_attr_set_saturation(camera_h camera, int level);
 : int camera_attr_get_saturation(camera_h camera, int *level);
 : int camera_attr_get_saturation_range(camera_h camera, int *min, int *max);
 : int camera_attr_set_sharpness(camera_h camera, int level);
 : int camera_attr_get_sharpness(camera_h camera, int *level);
 : int camera_attr_get_sharpness_range(camera_h camera, int *min, int *max);

[Version] 0.4.100
[Issue Type] New feature

Change-Id: Ib19b5a2ef7923d2b1529bf2a2cb51df1fa6c9eab
Signed-off-by: Jeongmo Yang <jm80.yang@samsung.com>