* Add PKCE support.

* Fix tests

* Update oauth2.md

* Rename usePkce

* Fix the BrokenComponent error

* Update oauth2.md

* Remove isCode variable. Remove uuid4 dependency.

* Remove utils functions

* Import crypto

* Fix tests

* Fix the tests

* Cleanup

* Fix code_challenge generation

* Move code challenge and verifier to utils for mocks. Update tests.

* Mock the PKCE methods in the utils file properly.

* Add missing expect

* use target-method spies

* Add comments to explain test values.

* Get rid of jsrsasign.

* add `getParameterSchema` OAS helper

* use `Parameter.content.[firstKey].schema` as schema value when present

* `newValue` -> `initialValue`

* make `paramWithMeta` a const

* add trailing comma to `swagger2SchemaKeys`

* refactor `helpers` to a folder

* deprecate `src/core/utils.js` in favor of `src/core/helpers/`

* support `Parameter.content.[mediaType].schema` in validateParam

* reject `null` as an OAS3 object value

* expose Fetch errors in the browser console

* generate ParameterRow default values based on `content` values

* add tests for `getParameterSchema`

* remove debugger statement

* remove debugger statement

* don't apply `generatedSampleValue`s to parameters with `examples`

* remove extra semi

* disable JSON check in parameter runtime validation

* stringify JsonSchema_object textarea values

* add Cypress tests

* swagger-client@3.9.4