SDK-417 generate json for experimenter from ir (#4656)

* [WIP] generate json for experimenter from ir

* adds tests for schema generation

* removes default featurs from jsonschema

* Adjust schema to accept key-value features

* Changes enum to string with enum variants

* cargo fmt

* fixes cli.yaml for experimenter

components/support/nimbus-fml/Cargo.toml

@@ -19,3 +19,4 @@ heck = "0.3.3"
 
 [dev-dependencies]
 tempdir = "0.3.7"
+jsonschema = { version = "0.13", default-features = false }

components/support/nimbus-fml/ExperimentFeatureManifest.schema.json

@@ -0,0 +1,82 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$ref": "#/definitions/Features",
+  "definitions": {
+    "Features": {
+      "patternProperties": {
+        "[a-zA-Z0-9_]+": {
+          "additionalProperties": false,
+          "type": "object",
+          "properties": {
+            "description": {
+              "type": "string"
+            },
+            "hasExposure": {
+              "type": "boolean",
+              "description": "If the feature sends an exposure event."
+            },
+            "exposureDescription": {
+              "type": "string",
+              "description": "A description of the implementation details of the exposure event, if one is sent."
+            },
+            "isEarlyStartup": {
+              "type": "boolean",
+              "description": "If the feature values should be cached in prefs for fast early startup."
+            },
+            "variables": {
+              "additionalProperties": false,
+              "type": "object",
+              "patternProperties": {
+                "[a-zA-Z0-9_]+": {
+                  "type": "object",
+                  "properties": {
+                    "type": {
+                      "type": "string",
+                      "enum": [
+                        "json",
+                        "boolean",
+                        "int",
+                        "string"
+                      ]
+                    },
+                    "fallbackPref": {
+                      "type": "string"
+                    },
+                    "enum": {
+                      "description": "Validate feature value using a list of possible options (for string only values)."
+                    },
+                    "description": {
+                      "type": "string",
+                      "description": "Explain how this value is being used"
+                    }
+                  },
+                  "required": [
+                    "type",
+                    "description"
+                  ],
+                  "additionalProperties": false
+                }
+              }
+            }
+          },
+          "required": [
+            "description",
+            "hasExposure"
+          ],
+          "if": {
+            "properties": {
+              "hasExposure": {
+                "const": true
+              }
+            }
+          },
+          "then": {
+            "required": [
+              "exposureDescription"
+            ]
+          }
+        }
+      }
+    }
+  }
+}