[CBR-391] launcher: add a workingDir setting to the launcher config

[rvl]

Description

Changing to the working directory before starting cardano-node allows other paths (nodeDbPath in particular) to be supplied as relative paths. This allows us to work around unicode bugs in rocksdb.

Linked issue

https://iohk.myjetbrains.com/youtrack/issue/CBR-391

Type of change

• 🐞 Bug fix (non-breaking change which fixes an issue)
• 🛠 New feature (non-breaking change which adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)
• 🏭 Refactoring that does not change existing functionality but does improve things like code readability, structure etc
• 🔨 New or improved tests for existing code
• ⛑ git-flow chore (backport, hotfix, etc)

Developer checklist

• I have read the style guide document, and my code follows the code style of this project.
• If my code deals with exceptions, it follows the guidelines.
• I have updated any documentation accordingly, if needed. Documentation changes can be reflected in opening a PR on cardanodocs.com, amending the inline Haddock comments, any relevant README file or one of the document listed in the docs directory.
• CHANGELOG entry has been added and is linked to the correct PR on GitHub.

Testing checklist

No automated tests for this. Needs to be checked by running with Daedalus.

QA Steps

1. Log in to Windows as user "ŮŝĕŗŃåɱĕ".
2. Start Daedalus (built with this code included).
3. Check that cardano-node.exe has not failed with some c_rocksdb_open error.