path manager

[leoyala]

The repo needs a path manager mechanism to manage how the most relevant paths are resolved across the entire package. The most important features are the following:

• The manager should be able to infer the path to the local store through the following mechanisms: env variables DSTRACK_ROOT_PATH, through a CLI provided path --root. If not provided by the user. Then search upwards in the folder structure until .dstrack/ folder is found, similar to how git resolves the root directory.
• The manager should also provide a structure validator for the local store to check that the consistency of the local store is correct.