* Introduce code style and reformat existing code #403

* Add check-code-style.yml workflow #403

* Add graphql-codegen-check-style.xml and enable it in the workflow #403

* Fix check-code-style.yml workflow

* Fix build issues

* Revert back changes in gradlew script

* fxi ParameterizedInput bug

* fix tostring

(cherry picked from commit f3fe479f)

* fxi ParameterizedInput bug

* fix tostring

* Optimize template

* add test

* support kotlin

* fix unit test

* fix scala

* add plugin, fix doc

* Do not use empty data class

* update

* update

* add unit test.
remove tostring

* update

* update

* update

* update

* refactor

* add unit test

* support option  any where.
https://github.com/kobylynskyi/graphql-java-codegen/issues/415

* add task  with kotlin in gradle

* 🚀 supportScalaOption for primitive type

* fix

* add unit test for scala Option

* change var name

* Complete Scala test

* For kotlin, 'getUseOptionalForNullableReturnTypes' is ignored, which is compatible with the nullable semantics of any graphql.

* add unit test

* Refactor for multi-language support #407

* SBT-plugin support for multi-language refactoring (#419)

* support sbt

* support sbt
Co-authored-by: 梦境迷离 <568845948@qq.com>

* Optimize equals

* 1. Refactoring `toString` and `equals` methods(Simplify code bloat caused by large number of fields).
2. For Scala(after that, kotlin will do the same), the `builder` is no longer generated by default.

* rm a invalid `if`

* rm a invalid `if`