マルチコーデックサイマルキャストの送信に対応する

[melpon]

r0,r1,r2 に対応するコーデックを a=rid: の pt= に基づいて生成するようにしました。
pt= が無い場合、最初に見つかった a=rtpmap: のコーデックを利用します（既存の動作と同じ）。

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This pull request includes several changes to the examples/sumomo files, focusing on improving the handling of optional parameters and updating the RTP (Real-time Transport Protocol) handling. It also includes updates to the CHANGES.md file and several changes to the proto/soracp.proto, include/sorac/, and src/ directories.

Updates to optional parameters handling:

• examples/sumomo/option.c: Added handling for video and audio options in the long_opts[] struct and in the sumomo_option_parse function. Also, a SET_OPTBOOL macro was introduced to simplify setting boolean options. [1] [2] [3] [4] [5]
• examples/sumomo/option.h: Added video and audio options to the SumomoOption struct.
• examples/sumomo/sumomo.c: Updated the main function to set video and audio options based on the parsed options.

Updates to RTP handling:

• examples/sumomo/sumomo.c: Replaced rtp_encoding_parameters with rtp_parameters in the State struct and updated the on_capture_frame function to use rtp_parameters. [1] [2] [3]
• examples/sumomo/util.cpp and examples/sumomo/util.h: Updated the sumomo_util_scale_simulcast function to take a scales array instead of a num_rids integer. [1] [2]
• include/sorac/signaling.hpp: Updated the GetRtpParameters method in the Signaling class.
• proto/soracp.proto: Updated the RtpEncodingParameters message and added the RtpParameters message. [1] [2]
• src/signaling.cpp: Updated the GetRtpParameters method and the handling of RTP parameters in the SignalingImpl class. [1] [2] [3]

Other changes:

• CHANGES.md: Added entries for supporting multi-codec simulcast transmission and updating protoc-gen-jsonif to support optional parameters.