API for creating a CodeBlock Statement directly

[anantharaman93]

Similar to how CodeBlock.of(...) which is equitant to CodeBlock.builder().add(...).build() is provided, kindly consider providing CodeBlock.ofStatement(...) which is equivalent to CodeBlock.builder().addStatement("...").build()

[baiyanlali]

We tried to add a static method in CodeBlock to creating a CodeBlockStatement directly. Please check it out #875

[wyyfffff]

We modify the code by add method of(CodeBlock codeBlock) and ofStatement(CodeBlock codeBlock)