Rename 'base' parachain to 'stout' (#125)

* Rename base parachain to stout

* Refactor some scripts and node files based on renaming base parachain to stout

* Format code using cargo fmt

* A few additional changes

* A few additional changes

* Fix XCM tests

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Co-authored-by: Pawan Singh Bisht <[email protected]>
Co-authored-by: Steve Degosserie <[email protected]>