Store uri template attribute for webclient to store in metrics

Created by: unintended

URI Template attribute is used by spring-boot-actuator to put proper uri template tags in metrics in WebClientExchangeTags.java

E.g. when the attribute is set, the uri metric tag will be /pets/{petId}/children instead of /pets/666/children?gender=male&name=Tom and will prevent flooding of monitoring systems with all path params/query params combinations.

The logic is the same as in DefaultWebClient's uri() method implementation:

Early I implemented similar logic for RestTemplate: https://github.com/OpenAPITools/openapi-generator/pull/3500

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