Duplicate language binding pages: java/java-codegen and javascript/javascript-codegen

[8bitpal]

Problem

Java and JavaScript codegen are each documented twice in consecutive nav entries:

• /sdks-tools/language-bindings/java — "Java Codegen" (674 lines)
• /sdks-tools/language-bindings/java-codegen — "Daml Codegen for Java" (602 lines)
• /sdks-tools/language-bindings/javascript — "JavaScript Codegen" (273 lines)
• /sdks-tools/language-bindings/javascript-codegen — "Daml Codegen for JavaScript" (271 lines)

In each pair, the pages appear to cover the same topic at similar depth.