Feature - option to select use cached devices when creating instance of manager

[blacava]

Hi,
I've been learning lots about your library with using it for a project of mine. Firstly, well done! It works great for me. I'm trying to trim down my http api calls and increase overall efficiency for my use, and in doing so I've been using the dump file. If my understanding is correct (and if it isn't, let me know), when a meross manager instance is created, it still finds devices, etc. I thought it would be handy to have an option when creating the meross manager to set True or False to use a cached device dump, and if True, set the dump file location. I understand that the instance has to be created first before the load from dump method can be used, but I wonder if it could be called within the manager init itself?

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