Support default nodeAffinity for subscriptions

[DebakelOrakel]

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[simu]

Please clean up the unnecessary files introduced by component update. Change itself looks good (I assume you've tested the config on the lab?)

[simu]

Please update the docs as well to note that we set a default node selector.

If you move the default config to the library you probably want to update https://github.com/appuio/component-openshift4-operators/blob/master/docs/modules/ROOT/pages/references/component-library.adoc#managedsubscription and https://github.com/appuio/component-openshift4-operators/blob/master/docs/modules/ROOT/pages/references/component-library.adoc#namespacedsubscription and it makes sense to mention the new default node selector in https://github.com/appuio/component-openshift4-operators/blob/master/docs/modules/ROOT/pages/references/parameters.adoc#subscription as well.