This PR refactors `branchName`, `commitMessage` and `prTitle` so that they are more easily editable and hopefully more understandable. By breaking each up into subsections, users can modify one part without needing to copy/paste the entire string.

Directly editing any of these fields will now be deprecated and a warning issued.

Closes #1626

Closes #1829

renovateRepository now returns “res” - the result of the current renovation, and “status” - the overall status of the repository.

packageRules selectors should only ever be inside a packageRule object, or at the top level of a preset. This feature enforces this rule with a validation check.

Closes #1773