break functionality up into subcommands

[0xalpharush]

Describe the desired feature

We should improve Slither's command line interface by replacing flags that are used to toggles "modes" into subcommands. This would allow for less noise in help menus. We should also cleanup the configurations and add additonal validation to ensure the behavior is intuitive yet configurable.

slither . --detect -> slither detect
slither . --print -> slither print

Perhaps tools could become subcommands instead of alternative entry points. This would allow us to make them opt-in i.e.
slither-read-storage would become slither read-storage and its dependencies would only be installed if you run pip install slither[read-storage]

Related (#759 #1458)