Make plugin compatible with SQLite

[bonny]

SQLite support may come to WordPress and Simple History must support it if that happens.

But let's wait a bit and see how development of feature plugin goes before implementing anything.

More info:

• SQLite Database Integration feature plugin
• GitHub repo for feature plugin
• Let’s make WordPress officially support SQLite

To check for sqlite feature plugin:

• https://github.com/WordPress/sqlite-database-integration/blob/main/db.copy
  • define( 'DATABASE_TYPE', 'sqlite' );
  • define( 'DB_ENGINE', 'sqlite' );

[bonny]

Maybe this should be prioritized because the preview playground uses sqlite and therefor simple history does not show any history:
https://playground.wordpress.net/?plugin=simple-history