Show result panel immediately when available.

In the QeAppWorkChain, it submits all plugin workchains in parallel in one step. This is good. But, it will only output the result when this step is finished, which means the result panel can not get results for the already finished plugins.
```python
cls.run_plugin,
cls.inspect_plugin,
```
### Improvement
Before, the plugin read the result from the sub-process of the plugin directly. But in order to simplify the unit test for the workchain, we removed it and used `out_many` to output the result to the QeAppWorkChain's result. We may consider moving it back and updating the method for the unit test.