Ensure RaftStore lock files are created and updated atomically

[deepthidevaki]

Describe the bug

We observed that on startup the lock file is empty, and this failed the startup of the partition with "Failed to acquire lock".
Possible reasons:

1. Pod crashed after creating the lock file, but before writing the lock info
2. Lock file was created and updated, but it was not flushed to disk before the pod restarted.

Workaround in this case is to delete the lock file and restart the pod. This is risky, because lock file exists to ensure that the directories are not shared by multiple pods. If we workaround it, we have to manually check if everything is configured correctly.

Expected behavior
The lock is not empty. Either lock file exists and have contents, or lock file does not exist.

Environment:

• Zeebe Version: 8.1.0