Refuse to start and print txn log information in case of disk corruption

Transaction logs were introduced by CASSANDRA-7066 and are read during start-up. In case of file system errors, such as disk corruption, we currently log a panic error and leave the sstable files and transaction logs as they are; this is to avoid rolling back a transaction (i.e. deleting files) by mistake.

We should instead look at the disk_failure_policy and refuse to start unless the failure policy is ignore.

We should also consider stashing files that cannot be read during startup, either transaction logs or sstables, by moving them to a dedicated sub-folder.