Sqlite3-to-mysql

* [FEAT] set default collation of newly created databases and tables to utf8mb4_general_ci
* [FEAT] optional transfer of implicit column rowid using --with-rowid
* [CHORE] test non-numeric primary keys
* [CHORE] add rowid transfer tests
* [CHORE] fix tests

* [FIX] fix information_schema issue introduced with MySQL 8.0.21
* [FIX] sqlalchemy-utils dropped Python 2.7 support in v0.36.7
* [CHORE] add MySQL version output to CI tests
* [CHORE] add Python 3.9 to the CI tests
* [CHORE] add MariaDB 10.5 to the CI tests
* [CHORE] remove Python 2.7 from allowed CI test failures
* [CHORE] use Ubuntu Bionic instead of Ubuntu Xenial in CI tests

* [FEAT] add support for SQLite STRING and translate it as MySQL TEXT

* [FIX] force not null on primary-key columns

* [CHORE] test legacy databases in CI tests
* [CHORE] fix MySQL 8 CI tests

* [FEAT] add option to transfer only specific tables using -t
* [CHORE] add tests for transferring only certain tables