Component-scoped configuration override. Pass into a component's or
directive's viewProviders; features merge on top of the parent config (an
enclosing scope or the application root), so one panel can re-scope its axis
subset or labels without disturbing the rest of the app. This is the
component-scope tier of the resolution cascade: provideA11yPanelConfigAt
(nearest) wins over provideA11yPanelConfig (root), which wins over the
library defaults.