Refactor file operations

[rflprr]

The way we have implemented file operations makes the app prone to reoccurring bugs. This applies to any file in a knot, but let's take catalog.json as an example, at any point it can live in ./, ./configs, ./{knot}/tap or ./knots/{knot}/tap (also, what ./ means, changes between dev and prod builds). Instead, I'd like us to change this so:

1. If a knot is saved, it lives in ./knots/{knot}
2. Knots being edited live in ./tmp/{uuid}
3. Knots being run stay in ./knots/{knot}
4. ./tmp is garbage collected aggressively (e.g. when app is opened/closed, when wizard is entered/exited, etc)