Changes to GET /v3/serp/youtube/video_subtitles/tasks_fixed

api operation id SerpYoutubeVideoSubtitlesTasksFixed removed and replaced with YoutubeVideoSubtitlesTasksFixed

api operation id YoutubeVideoSubtitlesTasksFixed removed and replaced with SerpYoutubeVideoSubtitlesTasksFixed

removed the optional property oneOf[#/components/schemas/SerpYoutubeVideoSubtitlesTasksFixedResponseInfo]/allOf[subschema #2]/tasks/items/oneOf[#/components/schemas/SerpYoutubeVideoSubtitlesTasksFixedTaskInfo]/allOf[subschema #2]/result/items/oneOf[#/components/schemas/SerpYoutubeVideoSubtitlesTasksFixedResultInfo]/date_fixed from the response with the 200 status

added the optional property oneOf[#/components/schemas/SerpYoutubeVideoSubtitlesTasksFixedResponseInfo]/allOf[subschema #2]/tasks/items/oneOf[#/components/schemas/SerpYoutubeVideoSubtitlesTasksFixedTaskInfo]/allOf[subschema #2]/result/items/oneOf[#/components/schemas/SerpYoutubeVideoSubtitlesTasksFixedResultInfo]/date_posted to the response with the 200 status