Bean: Use properties instead of property with key and value

[igarashitm]

I found some kamelets are using beans property with key and value style, for example
https://github.com/apache/camel-kamelets/blob/main/kamelets/mysql-sink.kamelet.yaml#L97-L108

But the schema doesn't allow it. RouteTemplateDefinition specifies NamedBeanDefinition for beans
https://github.com/apache/camel/blob/camel-3.20.x/dsl/camel-yaml-dsl/camel-yaml-dsl/src/generated/resources/schema/camel-yaml-dsl.json#LL2621C40-L2621C40

where NamedBeanDefinition has only properties with the type object
https://github.com/apache/camel/blob/camel-3.20.x/dsl/camel-yaml-dsl/camel-yaml-dsl/src/generated/resources/schema/camel-yaml-dsl.json#L339

Once additionalProperties: false is added to the schema (which is on table for doing on Camel4), this could end up with validation error. We'd want to align with schema before it happens.

Cc: @lburgazzoli

[oscerd]

Should be fine now.