Align WebClient uri metric tag with RestTemplate

Prior to this commit, the `WebClientExchangeTags`, when given a request
without a string template, would only get the request path to create the
"uri" tag for metrics. This is inconsistent with the
`RestTemplateExchangeTags`, which are taking the full request URI minus
the protocol+host+port.

This commit aligns the `WebClientExchangeTags` behavior in this case.

Closes gh-22832

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/web/reactive/client/WebClientExchangeTagsTests.java

@@ -78,6 +78,14 @@ class WebClientExchangeTagsTests {
 		assertThat(WebClientExchangeTags.uri(this.request)).isEqualTo(Tag.of("uri", "/projects/spring-boot"));
 	}
 
+	@Test
+	void uriWhenTemplateIsMissingShouldReturnPathWithQueryParams() {
+		this.request = ClientRequest
+				.create(HttpMethod.GET, URI.create("https://example.org/projects/spring-boot?section=docs")).build();
+		assertThat(WebClientExchangeTags.uri(this.request))
+				.isEqualTo(Tag.of("uri", "/projects/spring-boot?section=docs"));
+	}
+
 	@Test
 	void clientName() {
 		assertThat(WebClientExchangeTags.clientName(this.request)).isEqualTo(Tag.of("clientName", "example.org"));