Add eventprocessor syntax change

[TomasEkeli]

Today we write

dolittle add eventprocessor {name_of_new_eventprocessor}

I think it should be

dolittle add eventprocessor {existing_event}

And then either generate a processor with a convention-based name ({existing_event}_processor) or ask for a name.

Even better would be to not use add, but rather have a new command

dolittle process {existing_event}

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