Issue #2682533 by fago: Make config tag storage multiple.

config/schema/rules.schema.yml

src/Controller/RulesReactionListBuilder.php

src/Core/RulesEventManager.php

src/Engine/RulesComponent.php

src/Entity/ReactionRuleConfig.php

src/Entity/RulesComponentConfig.php

src/Form/RulesComponentFormBase.php

.../install/rules.component.rules_test_default_component.yml