Add configs for strict PHP checks

[provokateurin]

This is meant for new files in order to have top quality from the start. Of course it can also be used for existing files, but they should go through the normal psalm/rector configs first.

[CarlSchwan]

For psalm, I am still a bit more in favor or increasing the level and add more stuff to the baseline. This has a bit of the same effect. New code has higher quality requirements, old code has know defect we can slowly get rid of with time.

I feel like for new files, we will always forgot to add them to the list of new files.

[provokateurin]

For psalm, I am still a bit more in favor or increasing the level and add more stuff to the baseline. This has a bit of the same effect. New code has higher quality requirements, old code has know defect we can slowly get rid of with time.

I get your point, but we can't just set the level to 1 right now, as it would explode the baseline size. So for new code, it's much easier to have a separate config.

I feel like for new files, we will always forgot to add them to the list of new files.

That is probably true, but for example in my case I want to add whole a new app and it would be really useful to just have it all clean and tidy from the start, even if it's only used for that one app.