Support for distributions definitions encoded as JSON strings

doc/json_properties/exponential_distribution.json

+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "ExponentialDistribution",
+  "type": "object",
+  "properties": {
+      "lowerLimit": {
+          "type": "number",
+          "description": "Lower limit"
+      },
+      "upperLimit": {
+          "type": "number",
+          "description": "Upper limit"
+      },
+      "expectedValue": {
+          "type": "number",
+          "description": "Reciprocal of the rate parameter lambda"
+      }
+  },
+  "required": ["lowerLimit", "upperLimit", "expectedValue"]
+}
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