[Logs UI] Create API route to create ML categorization jobs

[Zacqary]

Part of #41509

Acceptance criteria

POST /api/infra/log_analysis/jobs/create

• This creates the three ML jobs required for the analysis screen.
• Each job will have a job ID that follows the format kibana.infra-ui.${spaceId}.${sourceId}.${jobType}. This format is deterministic so that when we check for the jobs' existence later, we know what the ID should be even if that job was removed or not successfully created.

interface CreateJobsRequest {
  data: {
    sourceId: string;
    categorizationFieldName: string;
    filterQuery?: string; // the UI would probably limit this to a event.dataset filter
    timeRange: {
      startTime: number;
      endTime: number;
    };
    runContinuously: boolean;
  };
}

interface CreateJobsSuccessResponse {
  data: {
    jobs: Array<{
      jobId: string;
      jobType: JobType;
      jobStatus: 'created';
    }>;
  };
}

type JobType = 'log_entry_rate' | 'rare_log_categories' | 'high_log_categories';

interface CreateJobsFailureResponse {
    errors: Array<HTTPError>;
}

interface HTTPError {
  statusCode: number;
  error: string;
  message: string;
  attributes?: Object;
}

[elasticmachine]

Pinging @elastic/infra-logs-ui

[weltenwort]

Given that the existing module API will be extended to support our requirements (#42409), there is no need for a custom API. Instead, the ml module's /api/ml/modules/setup/:moduleId route should be used.