Fix directory handling

[sisyphusSmiling]

Description

Currently, running swap with an assigned directory --swipe-dest or --swap-dest directory outside of the current or sub-directories results in read-only errors. This needs to be fixed before formalizing into a CLI package

Solution Criteria

The following should run without issue

python src/swipe-and-swap.py --repo onflow/flow-nft --swipe-dest ../my-repo/cadence/ --swap-dest ./src/cadence

Which would take the contract/ scripts/ and transactions/ from onflow/flow-nft, save them to ../my-repo/cadence/ then translate the contents to TypeScript consts in ./src/cadence. It should also be able to handle absolute paths in addition the previously mentioned relative paths.