Some directories are separate from --user-data-dir

### Steps to Reproduce

Set `--user-data-dir`.

### Expected

Everything should move to that directory.

### Actual

Some things move, but not:
- heartbeat
- coder-logs
- Generated certificates

### Workaround

You can set xdg data home environment variable instead of using the flag.

### Notes

Changing this could be considered be a breaking change? If someone was setting `--user-data-dir` but then relying on these files being in the other location. Not 100% sure how best to proceed. Maybe check if they exist, and if not use the new location, but even that could be breaking.

Maybe introduce a new flag and deprecate `--user-data-dir`.