Add equality method for RTCVideoCodecInfo.

This is useful for various reasons.

Bug: None
Change-Id: I8658f8b19829cc8470789c13ff3af6466f200f00
Reviewed-on: https://webrtc-review.googlesource.com/4383
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20018}

sdk/objc/Framework/Headers/WebRTC/RTCVideoCodec.h

@@ -105,6 +105,8 @@ RTC_EXPORT
                   parameters:(nullable NSDictionary<NSString *, NSString *> *)parameters
     NS_DESIGNATED_INITIALIZER;
 
+- (BOOL)isEqualToCodecInfo:(RTCVideoCodecInfo *)info;
+
 @property(nonatomic, readonly) NSInteger payload;
 @property(nonatomic, readonly) NSString *name;
 @property(nonatomic, readonly) NSDictionary<NSString *, NSString *> *parameters;