Fix cross-reference links in HtmlUnit sections

Closes gh-35853

Signed-off-by: Tran Ngoc Nhan <ngocnhan.tran1996@gmail.com>

framework-docs/modules/ROOT/pages/testing/mockmvc/htmlunit/geb.adoc

@@ -8,7 +8,7 @@ use https://www.gebish.org/[Geb] to make our tests even Groovy-er.
 == Why Geb and MockMvc?
 
 Geb is backed by WebDriver, so it offers many of the
-xref:testing/mockmvc/htmlunit/webdriver.adoc#spring-mvc-test-server-htmlunit-webdriver-why[same benefits] that we get from
+xref:testing/mockmvc/htmlunit/webdriver.adoc#mockmvc-server-htmlunit-webdriver-why[same benefits] that we get from
 WebDriver. However, Geb makes things even easier by taking care of some of the
 boilerplate code for us.
 
@@ -28,7 +28,7 @@ def setup() {
 ----
 
 NOTE: This is a simple example of using `MockMvcHtmlUnitDriverBuilder`. For more advanced
-usage, see xref:testing/mockmvc/htmlunit/webdriver.adoc#spring-mvc-test-server-htmlunit-webdriver-advanced-builder[Advanced `MockMvcHtmlUnitDriverBuilder`].
+usage, see xref:testing/mockmvc/htmlunit/webdriver.adoc#mockmvc-server-htmlunit-webdriver-advanced-builder[Advanced `MockMvcHtmlUnitDriverBuilder`].
 
 This ensures that any URL referencing `localhost` as the server is directed to our
 `MockMvc` instance without the need for a real HTTP connection. Any other URL is
@@ -62,7 +62,7 @@ forwarded to the current page object. This removes a lot of the boilerplate code
 needed when using WebDriver directly.
 
 As with direct WebDriver usage, this improves on the design of our
-xref:testing/mockmvc/htmlunit/mah.adoc#spring-mvc-test-server-htmlunit-mah-usage[HtmlUnit test] by using the Page Object
+xref:testing/mockmvc/htmlunit/mah.adoc#mockmvc-server-htmlunit-mah-usage[HtmlUnit test] by using the Page Object
 Pattern. As mentioned previously, we can use the Page Object Pattern with HtmlUnit and
 WebDriver, but it is even easier with Geb. Consider our new Groovy-based
 `CreateMessagePage` implementation:

framework-docs/modules/ROOT/pages/testing/mockmvc/htmlunit/mah.adoc

@@ -45,7 +45,7 @@ Kotlin::
 ======
 
 NOTE: This is a simple example of using `MockMvcWebClientBuilder`. For advanced usage,
-see xref:testing/mockmvc/htmlunit/mah.adoc#spring-mvc-test-server-htmlunit-mah-advanced-builder[Advanced `MockMvcWebClientBuilder`].
+see <<mockmvc-server-htmlunit-mah-advanced-builder>>.
 
 This ensures that any URL that references `localhost` as the server is directed to our
 `MockMvc` instance without the need for a real HTTP connection. Any other URL is
@@ -77,7 +77,7 @@ Kotlin::
 ======
 
 NOTE: The default context path is `""`. Alternatively, we can specify the context path,
-as described in xref:testing/mockmvc/htmlunit/mah.adoc#spring-mvc-test-server-htmlunit-mah-advanced-builder[Advanced `MockMvcWebClientBuilder`].
+as described in <<mockmvc-server-htmlunit-mah-advanced-builder>>.
 
 Once we have a reference to the `HtmlPage`, we can then fill out the form and submit it
 to create a message, as the following example shows:
@@ -144,7 +144,7 @@ Kotlin::
 ======
 
 The preceding code improves on our
-xref:testing/mockmvc/htmlunit/why.adoc#spring-mvc-test-server-htmlunit-mock-mvc-test[MockMvc test] in a number of ways.
+xref:testing/mockmvc/htmlunit/why.adoc#mockmvc-server-htmlunit-mock-mvc-test[MockMvc test] in a number of ways.
 First, we no longer have to explicitly verify our form and then create a request that
 looks like the form. Instead, we request the form, fill it out, and submit it, thereby
 significantly reducing the overhead.

framework-docs/modules/ROOT/pages/testing/mockmvc/htmlunit/webdriver.adoc

@@ -203,7 +203,7 @@ Kotlin::
 ======
 
 NOTE: This is a simple example of using `MockMvcHtmlUnitDriverBuilder`. For more advanced
-usage, see xref:testing/mockmvc/htmlunit/webdriver.adoc#spring-mvc-test-server-htmlunit-webdriver-advanced-builder[Advanced `MockMvcHtmlUnitDriverBuilder`].
+usage, see <<mockmvc-server-htmlunit-webdriver-advanced-builder>>.
 
 The preceding example ensures that any URL that references `localhost` as the server is
 directed to our `MockMvc` instance without the need for a real HTTP connection. Any other
@@ -259,9 +259,8 @@ Kotlin::
 ======
 --
 
-This improves on the design of our xref:testing/mockmvc/htmlunit/mah.adoc#spring-mvc-test-server-htmlunit-mah-usage[HtmlUnit test]
-by leveraging the Page Object Pattern. As we mentioned in
-xref:testing/mockmvc/htmlunit/webdriver.adoc#mockmvc-server-htmlunit-webdriver-why[Why WebDriver and MockMvc?], we can use the Page Object Pattern
+This improves on the design of our xref:testing/mockmvc/htmlunit/mah.adoc#mockmvc-server-htmlunit-mah-usage[HtmlUnit test]
+by leveraging the Page Object Pattern. As we mentioned in <<mockmvc-server-htmlunit-webdriver-why>>, we can use the Page Object Pattern
 with HtmlUnit, but it is much easier with WebDriver. Consider the following
 `CreateMessagePage` implementation: