VideoCommon: store the configuration used to create the AbstractPipeline

[iwubcode]

This allows us to re-create the pipeline easily (with tweaked changes). used in #11300

[phire]

It feels slightly sub-optimal to set the AbstractPipeline's config after it's created.

1. It creates a potential foot-gun where a user of the CreatePipeline function forgets to set the config (and I kind of want to expose Abstract stuff via the scripting interface on my scripting branch)
2. The memory needs to be written twice. First clearing to zero during initialisation and then copying the data into it a second time.

[iwubcode]

Thanks @phire for looking it over. I considered doing this in CreatePipeline() originally, can't remember why I didn't go with that. I will take another look.

[phire]

can't remember why I didn't go with that. I will take another look.

Probably because it would have involved making the same change in 6 different files.

[iwubcode]

Ah yeah. Then I considered doing an "impl" pattern but chickened out. Guess I'll wait on your KillRenderer before making those changes.