[Rust] Generate imports in alphabetical order.

Author: gierlachg

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/LibRsDef.java

@@ -73,6 +73,7 @@ void generate() throws IOException
                     .filter((fileName) -> fileName.endsWith(".rs"))
                     .filter((fileName) -> !fileName.equals("lib.rs"))
                     .map((fileName) -> fileName.substring(0, fileName.length() - 3))
+                    .sorted()
                     .forEach(modules::add);
             }
 

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/RustGenerator.java

@@ -152,8 +152,8 @@ public void generate() throws IOException
             try (Writer out = outputManager.createOutput(codecModName))
             {
                 indent(out, 0, "use crate::*;\n\n");
-                indent(out, 0, "pub use encoder::%sEncoder;\n", formatStructName(msgToken.name()));
-                indent(out, 0, "pub use decoder::%sDecoder;\n\n", formatStructName(msgToken.name()));
+                indent(out, 0, "pub use decoder::%sDecoder;\n", formatStructName(msgToken.name()));
+                indent(out, 0, "pub use encoder::%sEncoder;\n\n", formatStructName(msgToken.name()));
                 final String blockLengthType = blockLengthType();
                 final String templateIdType = rustTypeName(ir.headerStructure().templateIdType());
                 final String schemaIdType = rustTypeName(ir.headerStructure().schemaIdType());