Allow genesis presets to be patched

[clangenb]

The current presets are not very flexible. The entire thing is hardcoded, it would be good if we can add minor changes on top of them like the para-id, see #7481 (comment).

In the kitchensink-node we would also benefit from tweaking the staking set up on top of the base genesis preset, see #7741 (comment).

cc @michalkucharczyk

[michalkucharczyk]

Yeah, ideally if presets/more patches could be stacked.

To be more precise in (#7481 (comment)) I meant support for the following scenario:

GenericChainSpec::builder(...)
  .with_genesis_config_preset_name("dev")
  .with_genesis_config_patch(patch1)
  .with_genesis_config_patch(patch2)
  .with_genesis_config_patch(patch3)

Should be relatively easy to add. Internally it should use GenesisConfigBuilderRuntimeCaller::get_named_preset + json_patch::merge. Probably some refactoring around GenesisBuildAction would be needed (new action or maybe preset variant could be extended with optional patches 🤔 ).

[bkchr]

@clangenb do you want to work on this?

[clangenb]

Yes, this sounds indeed like an interesting task to work on.

However, I would like to frankly mention that I will start asking for tips. My fellowship Rank I salary is miserable considering the amount of work I have been doing lately, and the tips have been scarce. ;)