feature: support for Parameter.content (#5571)

* 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

package-lock.json

@@ -21100,9 +21100,9 @@
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+      "version": "3.9.4",
+      "resolved": "https://registry.npmjs.org/swagger-client/-/swagger-client-3.9.4.tgz",
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         "@kyleshockey/object-assign-deep": "^0.4.0",
@@ -21125,9 +21125,9 @@
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+          "resolved": "https://registry.npmjs.org/buffer/-/buffer-5.4.2.tgz",
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