clean: Park/cleanup sqlite databases

[cgwalters]

I recently discovered that libdnf has its own sqlite database in /usr/lib/sysimage/libdnf5/transaction_history.sqlite. This has the same problem as rpm-software-management/rpm#2219

Basically something like dnf clean all should automatically park both databases.

[ppisar]

Removing the transaction_history.sqlite-shm and transaction_history.sqlite-wal files creates a risk of a race with another DNF process using that database. We will need to scrutinize "dnf clean all" regarding ensuring an exclusive write and read access to the transaction_history database.

Pointers for further investigation:

https://www.sqlite.org/wal.html
SQLite3::open() in libdnf5/utils/sqlite3/sqlite3.cpp

I don't think DNF is going to touch RPM database directly. RPM would need first expose that cleanup feature through its API and then "dnf clean all" could use it.