turnip: Execute main cs for secondary command buffers

Previously, we only added the secondary command buffer's draw and draw epilogue command streams to the primary command buffer on vkCmdExecuteCommands. However, we also need to merge the primary cs for non-draw operations like vkCmdCopyBuffer and vkCmdBeginQuery.

Fixes dEQP-VK.memory.pipeline_barrier.host_write_transfer_src.* and various other tests in dEQP-VK.api.command_buffers.*.