feat(functions): Allow for using JSON in functions

Author: acco

docs/snippets/function-transform-snippet.mdx

@@ -42,6 +42,7 @@ The function transform allows you to use a subset of the Elixir standard library
 - [Decimal](https://hexdocs.pm/decimal/readme.html)
 - [URI](https://hexdocs.pm/elixir/URI.html)
 - [Base](https://hexdocs.pm/elixir/Base.html)
+- [JSON](https://hexdocs.pm/elixir/JSON.html)
 
 In addition to the standard library modules, you can also use certain other dependencies:
 

lib/sequin/functions/minielixir/validator.ex

@@ -303,6 +303,7 @@ defmodule Sequin.Functions.MiniElixir.Validator do
   defp fnok([URI, _]), do: :ok
   defp fnok([Base, _]), do: :ok
   defp fnok([UUID, _]), do: :ok
+  defp fnok([JSON, _]), do: :ok
   defp fnok(p), do: {:error, :validator, "Forbidden function: #{redot(p)}"}
 
   # Convert left-associated instances of the . operator to a get_in path