[video_player_avplay] Add error event

[xiaowei-guan]

Add player error event for app:

/// Specifies the player error messages.
enum PlayerError {
  /// Operation has successfully completed; no error.
  none,

  /// Out of memory.
  outOfMemory,

  /// Unable to find the parameter.
  invalidParameter,

  /// Unable to find the specified media content.
  noSuchFile,

  /// Invalid API Call at the moment.
  invalidOperation,

  /// No space left on the device.
  fileNoSpaceOnDevice,

  /// Not supported Feature.
  featureNotSupportedOnDevice,

  /// Failed to perform seek operation, or seek operation called during an
  /// invalid state
  seekFailed,

  /// AVPlay API method was called during an invalid state.
  invalidState,

  /// Multimedia file type not supported.
  notSupportedFile,

  /// Input URI is in an invalid format.
  invalidUri,

  /// Sound policy error.
  soundPolicy,

  /// Failed multiple attempts to connect to the specified content server.
  connectionFailed,

  /// Expired license.
  drmExpired,

  /// License for future use.
  drmFutureUse,

  /// No license.
  drmNoLicense,

  /// Format not permitted.
  drmNotPermitted,

  /// Resource limit.
  resourceLimit,

  /// Permission denied.
  permissionDenied,

  /// Socket connection lost.
  serviceDisconnected,

  /// No buffer space available.
  bufferSpace,

  /// Not supported audio codec but video can be played.
  notSupportedAudioCodec,

  /// Not supported video codec but audio can be played.
  notSupportedVideoCodec,

  /// Not supported subtitle format.
  notSupportedSubtitle,

  /// Multimedia file format not supported.
  notSupportedFormat,
}

[JSUYA]

I applied this PR and tested to disconnect the network situation when dash video playing. (unpluged cable)
I expected _controller.value.playerError of addListener to be connectionFailed, but _controller.value.playerError is always none. Is there a specific os version or plusplayer lib version that does not receive the error message? (my device is tizen 9.0)

And the existing hasError/errorDescription and this playerError looks duplicated.
Isn't it better to set errorDescription than to set playerError value? Is it because of the enum type?

[xiaowei-guan]

I applied this PR and tested to disconnect the network situation when dash video playing. (unpluged cable) I expected _controller.value.playerError of addListener to be connectionFailed, but _controller.value.playerError is always none. Is there a specific os version or plusplayer lib version that does not receive the error message? (my device is tizen 9.0)

And the existing hasError/errorDescription and this playerError looks duplicated. Isn't it better to set errorDescription than to set playerError value? Is it because of the enum type?

Sorry, I just verified the PR with HSL stream, I also can't get connfication failed with Dash stream, I will check with MM team.