Sync deletions with the native sync as well

[Vitor-Avila]

Current Scenario

Currently, the sync native command can be used to push assets to Superset. This command imports all YAMLs from the specified path. However, this approach doesn't sync deletions.

Suggested Improvement

After a successful sync, the CLI could create a .history file to keep track of which assets were synced. In the next sync, the CLI could delete any asset that was previously synced (and therefore exists in the .history file) but was not synced anymore (so the YAML was likely deleted from the directory).

This behavior should be behind a command flag (the sync by default shouldn't delete assets).