Add .bonnie.cache.json

[arctic-hen7]

This would be implemented later in future, but I propose a system whereby very large Bonnie config files that don't change often can have the entire Bonnie parsing system run on them and the output cached into a file like .bonnie.cache.json. We could then read directly from this file, making future command runs much faster. We could also store the bonnie.toml file's hash, allowing us to update if it changes. Right now, this isn't an issue, but if and when ordered domain execution is finalised, processing speed could become a significant issue for configurations with complex control flows.

[arctic-hen7]

For complex control flows, regular expression parsing slows configuration parsing down significantly (around 100ms for full execution of the testing file), so this feature is now being implemented.