Proposal: add a flag for whether Daily.init has been called

[edison-rgb]

Calling Daily.init() twice will cause a hard crash of the python program, while there seems to be no way of checking whether it has been called. If we call Daily.init() ourself, we can easily track it with some sort of global variable, but if another library calls Daily.init(), e.g. pipecat, there's no robust way to keep track of that. We can try to tap into the internals of pipecat or other 3rd-party libraries, but that's rather brittle.

I think Daily.init() should either be made safe to call multiple times (add some internal check), or provide a truly global flag, like Daily.is_init.