Add missing call method, rename new call method

The Smithy Kotlin generator uses the call method which was removed
during the refactor. Adding that back, and renaming the newly added call
method that just statically types a `Consumer` to a method named
`consumer`.

smithy-utils/src/main/java/software/amazon/smithy/utils/AbstractCodeWriter.java

@@ -1432,16 +1432,29 @@ public final String format(Object content, Object... args) {
      * <p>You can write:
      *
      * <pre>{@code
-     * writer.write("$C", writer.call(w -> w.write("Hi"));
+     * writer.write("$C", writer.consumer(w -> w.write("Hi"));
      * }</pre>
      *
      * @param consumer The consumer to call.
      * @return Returns the consumer as-is, but cast as the appropriate Java type.
      */
-    public Consumer<T> call(Consumer<T> consumer) {
+    public Consumer<T> consumer(Consumer<T> consumer) {
         return consumer;
     }
 
+    /**
+     * Allows calling out to arbitrary code for things like looping or
+     * conditional writes without breaking method chaining.
+     *
+     * @param task Method to invoke.
+     * @return Returns the CodeWriter.
+     */
+    @SuppressWarnings("unchecked")
+    public final T call(Runnable task) {
+        task.run();
+        return (T) this;
+    }
+
     /**
      * Writes text to the CodeWriter and appends a newline.
      *
@@ -1673,7 +1686,7 @@ String applyFormatter(char identifier, Object value) {
             // A single trailing newline is stripped from the result, if present. This is because the $C formatter
             // is often used on the same line as other text like:
             //
-            //     w.write("Hi, $C.", w.call(writer -> writer.write("name");
+            //     w.write("Hi, $C.", w.consumer(writer -> writer.write("name");
             //     // Results in "Hi, name.\n" and not "Hi, name\n.\n"
             //
             // In these cases, the trailing newline introduced in the $C formatter by writer.write() is removed

smithy-utils/src/test/java/software/amazon/smithy/utils/CodeFormatterTest.java

@@ -474,7 +474,7 @@ public void cFormaterAcceptsConsumersThatAreCodeWriters() {
     @Test
     public void cFormatterAcceptsConsumersThatAreSubtypesOfCodeWriters() {
         CodeWriterSubtype w = new CodeWriterSubtype();
-        w.write("$C", w.call(writer -> writer.write2("Hello!")));
+        w.write("$C", w.consumer(writer -> writer.write2("Hello!")));
 
         assertThat(w.toString(), equalTo("Hello!\n"));
     }