Tables with dots in the name break import

[tresf]

It's common for SQL Server to use dot-notation for naming tables, but this is not common for MySQL and require special escaping which is largely frowned upon.

For example:

A table named Sales.Customers in Microsoft SQL would translated to Database: Sales, Table: Customers and break on INSERT unless wrapped with backticks. e.g. `Sales.Customers` explained further here: https://stackoverflow.com/a/776141/3196753

By default, we should replace dots . in table names with underscores _.