Refactor microblog accounts setup and updates into a MicroblogManager

Most of this code is currently in the MetricsBot class directly, with the setup in the main method.

The microblog(MicroblogStatus) and error(String) functions should be moved. Also, there should be new functions that also serve for logging:

debug(String)
info(String)
warning(String)
relay(String)
network(String)
alert(String)
event(String)

This will depend on #24075 (closed) to have the StatusTypes available. It will probably also depend on #24076 in order to have the logging to the console functionality.

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