Improve management of database at start of application

Summary:
add smooth upgrade for users with database matching v0.3.0 of Elisa

improve logging about database upgrades at start of Elisa

checks database schema and resets it in case of errors

BUG: 404458

improve logs about database creation

Test Plan:
no reindexing is necessary if user upgrades from v0.3.0

in case database schema is incorrect, it gets reset and indexing works fine

Reviewers: ngraham

Differential Revision: https://phabricator.kde.org/D20134