bazel syntax: move Printer.{repr,str,format,formatWithList} to Starlark

These fundamental API operations belong in class Starlark.

Also, this prepares the way for renaming
skylarkinterface.SkylarkPrinter to syntax.Printer by avoiding conflict
between static methods and future interface methods.

The little-used debugPrint operation was not thus moved.

This is a breaking change for copybara.

PiperOrigin-RevId: 282054622
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Tuple.java b/src/main/java/com/google/devtools/build/lib/syntax/Tuple.java
index dbee242..b0bad85 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Tuple.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Tuple.java
@@ -172,7 +172,7 @@
   // TODO(adonovan): SkylarkValue has 3 String methods yet still we need this fourth. Why?
   @Override
   public String toString() {
-    return Printer.repr(this);
+    return Starlark.repr(this);
   }
 
   @Override