Make CodeWriters intercept Object instead of String

This commit makes CodeWriter section interceptors deal with Object
instead of String. This allows for the toString() method of the
intercepted text to be wrapped by classes that extend from CodeWriter in
order to determine if any side effects from the original content should
take effect or be discarded. The general idea is that if toString() was
called on the original content of an intercepted section, then original
contents are also going to be written to the CodeWriter, meaning any
side effects should also occur (for example, adding imports).

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

@@ -302,7 +302,7 @@
  *
  * <pre>{@code
  * CodeWriter writer = CodeWriter.createDefault();
- * writer.onSection("example", text -> writer.write("Intercepted: " + text"));
+ * writer.onSection("example", text -> writer.write("Intercepted: " + text));
  * writer.pushState("example");
  * writer.write("Original contents");
  * writer.popState();
@@ -326,7 +326,7 @@
  *
  * <pre>{@code
  * CodeWriter writer = CodeWriter.createDefault();
- * writer.onSection("example", text -> writer.write("Intercepted: " + text"));
+ * writer.onSection("example", text -> writer.write("Intercepted: " + text));
  * writer.write("Leading text...${L@example}...Trailing text...", "foo");
  * System.out.println(writer.toString());
  * // Outputs: "Leading text...Intercepted: foo...Trailing text...\n"
@@ -535,8 +535,8 @@ public CodeWriter popState() {
             String result = getTrimmedPoppedStateContents(popped);
 
             if (popped.interceptors.containsKey(popped.sectionName)) {
-                List<Consumer<String>> interceptors = popped.interceptors.get(popped.sectionName);
-                for (Consumer<String> interceptor : interceptors) {
+                List<Consumer<Object>> interceptors = popped.interceptors.get(popped.sectionName);
+                for (Consumer<Object> interceptor : interceptors) {
                     result = expandSection("__" + popped.sectionName, result, interceptor);
                 }
             }
@@ -602,7 +602,7 @@ private String getTrimmedPoppedStateContents(State state) {
      * @param interceptor The function to intercept with.
      * @return Returns the CodeWriter.
      */
-    public CodeWriter onSection(String sectionName, Consumer<String> interceptor) {
+    public CodeWriter onSection(String sectionName, Consumer<Object> interceptor) {
         currentState.putInterceptor(sectionName, interceptor);
         return this;
     }
@@ -1032,7 +1032,7 @@ public Object getContext(String key) {
     }
 
     // Used only by CodeFormatter to expand inline argument sections.
-    String expandSection(String sectionName, String defaultContent, Consumer<String> writerConsumer) {
+    String expandSection(String sectionName, String defaultContent, Consumer<Object> writerConsumer) {
         StringBuilder buffer = new StringBuilder();
         pushState(sectionName);
         currentState.isInline = true;
@@ -1065,7 +1065,7 @@ private final class State {
         private boolean copiedContext = false;
 
         /** The interceptors map implements a simple copy on write pattern. */
-        private Map<String, List<Consumer<String>>> interceptors = MapUtils.of();
+        private Map<String, List<Consumer<Object>>> interceptors = MapUtils.of();
         private boolean copiedInterceptors = false;
 
         State() {}
@@ -1105,7 +1105,7 @@ void removeContext(String key) {
             }
         }
 
-        void putInterceptor(String section, Consumer<String> interceptor) {
+        void putInterceptor(String section, Consumer<Object> interceptor) {
             if (!copiedInterceptors) {
                 interceptors = new HashMap<>(interceptors);
                 copiedInterceptors = true;