Allow for custom system phases and system pipelines about flecs HOT 1 CLOSED

// Creates pipeline object
//
ecs_entity_t ecs_new_pipeline(world, ecs_pipeline_t* pipeline, const char* id);

// Deletes given pipeline
//
ecs_delete_pipeline(ecs_world_t* world, ecs_entity_t pipeline);

// Runs given pipeline with given delta time and optional param
//
ecs_run_pipeline(ecs_world_t* world, ecs_entity_t pipeline, float delta_time,
    void *param);

ecs_entity_t pipeline = ecs_new_pipeline(world, &(ecs_pipeline_t){
    .phases = {Tag_1, Tag_2, Tag_3},
    .bind_thread = {{-1}, {-1}, {0}},
    .stage = {true, true, false}
}, "Pipeline");

ECS_SYSTEM(world, Move, Tag_2, Position, Velocity);

ecs_run_pipeline(world, pipeline, delta_time, user_data);

ecs_delete_pipeline(world, pipeline);