Add FreeMarker macro support in spring-webflux

Closes gh-23002

spring-webflux/src/test/resources/org/springframework/web/reactive/result/view/freemarker/test-macro.ftl

@@ -0,0 +1,82 @@
+<#--
+test template for FreeMarker macro test class
+-->
+<#import "spring.ftl" as spring />
+
+NAME
+${command.name}
+
+AGE
+${command.age}
+
+MESSAGE
+<@spring.message "hello"/> <@spring.message "world"/>
+
+DEFAULTMESSAGE
+<@spring.messageText "no.such.code", "hi"/> <@spring.messageText "no.such.code", "planet"/>
+
+MESSAGEARGS
+<@spring.messageArgs "hello", msgArgs/>
+
+MESSAGEARGSWITHDEFAULTMESSAGE
+<@spring.messageArgsText "no.such.code", msgArgs, "Hi"/>
+
+URL
+<@spring.url "/aftercontext.html"/>
+
+URLPARAMS
+<@spring.url relativeUrl="/aftercontext/{foo}?spam={spam}" foo="bar" spam="bucket"/>
+
+FORM1
+<@spring.formInput "command.name", ""/>
+
+FORM2
+<@spring.formInput "command.name", 'class="myCssClass"'/>
+
+FORM3
+<@spring.formTextarea "command.name", ""/>
+
+FORM4
+<@spring.formTextarea "command.name", "rows=10 cols=30"/>
+
+FORM5
+<@spring.formSingleSelect "command.name", nameOptionMap, ""/>
+
+FORM6
+<@spring.formMultiSelect "command.spouses", nameOptionMap, ""/>
+
+FORM7
+<@spring.formRadioButtons "command.name", nameOptionMap, " ", ""/>
+
+FORM8
+<@spring.formCheckboxes "command.stringArray", nameOptionMap, " ", ""/>
+
+FORM9
+<@spring.formPasswordInput "command.name", ""/>
+
+FORM10
+<@spring.formHiddenInput "command.name", ""/>
+
+FORM11
+<@spring.formInput "command.name", "", "text"/>
+
+FORM12
+<@spring.formInput "command.name", "", "hidden"/>
+
+FORM13
+<@spring.formInput "command.name", "", "password"/>
+
+FORM14
+<@spring.formSingleSelect "command.name", options, ""/>
+
+FORM15
+<@spring.formCheckbox "command.name"/>
+
+FORM16
+<@spring.formCheckbox "command.jedi"/>
+
+FORM17
+<@spring.formInput "command.spouses[0].name", ""/>
+
+FORM18
+<@spring.formCheckbox "command.spouses[0].jedi" />