[image_picker] Refactor the C++ code

[swift-kim]

Part of the code refactoring project.

image_picker_tizen_plugin.cc

• Create a class PermissionManager as a replacement for CheckPermissionAndPickContent.
  • The class is a wrapper of the Tizen PPM API and provides two methods: CheckPermission and RequestPermssion.
  • Note that RequestPermssion is a blocking method.
  • The code will be shared by multiple packages. The CheckPermission method is not used by this package but is for use by other packages.
  • The return types of the methods are PermissionStatus and PermissionResult respectively.
  • The methods return kAllow or kAllowForever when compiled for TV.
• Use the GetValueFromEncodableMap template function to process method call arguments.
• Remove SetContentMimeType and let PickContent take mime_type as an argument.
• Minor cleanups.
  • SendResultWithSuccess/SendResultWithError → SendResult/SendErrorResult
  • Organize error codes and error messages in a consistent manner.
  • Move the non-public implementation into an anonymous namespace.

image_resize.cc

• Simplify the method Resize and move many of its parts to individual methods DecodeImage, TransformImage, and EncodeImage as appropriate. For example, the decode handle is created by DecodeImage but not Resize.
• Rename local variables in a consistent manner to make the code more readable.
• Create a private method IsValidQuality.
• Always use an explicit type uint32_t instead of unsigned int.
• Minor cleanups.
  • Format log messages consistently.
  • Inline the implementation of SetSize in the definition.
  • Remove a TODO regarding image_util_decode_set_colorspace.

[bbrto21]

• The code will be shared by multiple packages. The CheckPermission method is not used by this package but is for use by other packages.

How do you plan to support multiple packages?

[swift-kim]

How do you plan to support multiple packages?

The files will be copied to each package's (camera and geolocator) directory.