venus: add VN_PERF options for performance tuning

1st commit refactors debug option to struct vn_env

2-4 commits add perf options:

• no_async_set_alloc for !12501 (merged)
• no_async_buffer_create for !13428 (merged)
• no_asyc_queue_submit for !14657 (merged)

5th commit refactors vn_cmd_submit

6th commit adds a separate VN_DRAW_CMD_BATCH_LIMIT option to venus cmd batch traffic tuning

• e.g. adb shell setprop mesa.vn.draw.cmd.batch.limit 100

TEST:

• no behavior change without enabling perf options
• enable and test each perf option works as intended