Change how system.rs imports blocks to avoid merge conflicts

[User344]

This PR fixes potential merge conflicts in other PR's by removing including blocks by name in system.rs and using block mod that I implemented.

Just doing

use crate::{
	*,
	prelude::{fmt, Arc, Box, Bytes, FromStr, Rc, String, ToString},
    types::{DelayType, Encoding},
}

would also suffice, but I don't like just including everything.

This seems like a good solution, considering that we will be refactoring the way we include modules soon either way.

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Platform	Name	Status	Details
All	Formatting	✅	Details
Linux	Build library	✅	Details
Linux	Build binaries	✅	Details
Linux	Build tests	✅	Details
Linux	Build examples	✅	Details
Linux	Run tests	⏩	Details
Linux	Run doctests	⏩	Details