hdb-sqlite: choose table names through configuration (or at least optional prefixes for them)

[svmhdvn]

Is your feature request related to a problem? Please describe. Currently, lib/hdb/hdb-sqlite.c hardcodes the table names for Version, Principal, and Entry. It would be nice to choose our own names for them, or at least a unifying prefix, so that Heimdal can use an existing database file that contains other things. This will help with centralizing data for those who desire to do so, rather than having a separate heimdal-specific database file.

Describe the solution you'd like Add a new configuration option somewhere to krb5.conf that would allow us to set a string prefix for these table names. If possible, this might be reusable for other hdb backends.

Describe alternatives you've considered Hardcode a HDB_ prefix to them so that they (ideally) won't conflict with other table naming schemes. Presumably, this would require a bump for the version number.

Additional context N/A

[nicowilliams]

Yes, this would be nice. It shouldn't be difficult.