* feat(ISSUE-11033): add null encodable type and mustache changes
* feat(ISSUE-11033): regen all swift5 samples
* feat(ISSUE-11033): add swift5 examples of null encodable
* feat(ISSUE-11033): fix hashable and compliation issues
* fix(ISSUE-11033): fix tests by using new enum encodeValue
* fix(ISSUE-11033): fix tests by using new enum encodeValue
* fix(ISSUE-11033): revert status back in pet api test
* fix(ISSUE-11033): fix issue with objc compat generator
* feat(ISSUE-11033): restore default values to null encodables
* chore(ISSUE-11033): rename default value for null encodable
* chore(ISSUE-11033): add test cases with different nullable defaults
* [swift5] fix issue with form data with null file
* [swift5] fix issue with form data with null file on alamofire implementation
* [swift5] update sample projects
* [swift5] fix issue with form data with null file on alamofire implementation
* [swift5] add support for form url enconded in URLSession
* [swift5] add support for form url enconded in Alamofire
* [swift] improve code formatting
* [swift] improve code formatting
* [swift] dont defaut to application/json