Mysql-to-sqlite3

* [FIX] fix information_schema issue introduced with MySQL 8.0.21
* [FIX] fix MySQL 8 bug where column types would sometimes be returned as bytes instead of strings
* [FIX] sqlalchemy-utils dropped Python 2.7 support in v0.36.7
* [CHORE] use MySQL Client instead of PyMySQL in tests
* [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
* [CHORE] use Ubuntu Xenial only for MariaDB 10.4 CI tests
* [CHORE] test legacy databases in CI tests

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

* [FIX] duplicate foreign keys

* [FIX] properly escape SQLite index names
* [FIX] fix SQLite global index name scoping
* [CHORE] test the successful transfer of an unorthodox table name
* [CHORE] test the successful transfer of indices with same names

* [FIX] differentiate better between MySQL and SQLite errors
* [CHORE] add Python 3.8 and 3.8-dev test build

* [CHORE] add support for Python 3.8
* [CHORE] update mysql-connector-python to a minimum version of 8.0.18 to support Python 3.8
* [CHORE] update development dependencies
* [CHORE] add [bandit](https://github.com/PyCQA/bandit) tests