[139] Unique param storage key based on input configuration

[lucasdinonolte]

Context

As described in #139 changes to the input's configuration of a function can cause bugs when the previously cached input values aren't compatible with the new input's configuration anymore.

What this does

• adds a utility method that generates a hash from the string representation of an object
• uses this method to generate a hash based on a functions current input configuration
• adds that hash to that function's localStorage key, so it becomes df_functionName_hash
  • this makes sure that any changes to the input's config of a function will cause mechanic to create a fresh params cache

Closes #139

[runemadsen]

Excellent! I think this is ready to go.