[Java][Resttemplate] Normalize the RestTemplate ApiClient

Is your feature request related to a problem? Please describe.

Checking all Java clients, the only one that defines the ApiClient and XXXApi with the @Component annotation is RestTemplate.

With this change, now for RestTemplate (as it is done for the rest of the Java clients) we will have to define one bean as ApliClient and another one as XXXClient.

Describe the solution you'd like

Remove @Component from ApiClient.mustache and api.mustache

• ApiClient.mustache https://github.com/OpenAPITools/openapi-generator/blob/a4b5b850670ea8b5df193501f9e10e8f308ac51e/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache#L84

• api.mustache https://github.com/OpenAPITools/openapi-generator/blob/a4b5b850670ea8b5df193501f9e10e8f308ac51e/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/api.mustache#L30