dsctl bdb2mdb should cleanly fail if bundled libdb is not avaiable

[progier389]

Issue Description
When 389-ds-base-bdb is not installed (i.e if libdb is not installed) the database format conversion tools(dsctl bdb2mdb and dsctl mdb2bdb should be cleanly disabled

Package Version and Platform:

• Platform: CentOS/Redhat 10
• Package and version: 3.1

Additional context

Be careful thar the code should work for 2.5, 3.0 on Fedora (that requires the libdb rpm and ELN 10 that relie on the optionnal 389-ds-base-bdb rpm that contains the bundled library

[progier389]

Triaged: https://issues.redhat.com/browse/IDMDS-4494

[progier389]

5fa26ea..92eadd1 main -> main
3be01de..2b58908 389-ds-base-3.0 -> 389-ds-base-3.0