Update index name quoting in MySQL table creation

When creating a table that includes an index named with a reserved keyword the index name isn't quoted. When creating the index specifically the name is quote. This bring the table generation SQL inline with the index generation.
Also please test units as atomic as possible. Please add a test that directly tests `AbstractPlatform::getCheckDeclarationSQL()` and one that directly tests `AbstractPlatform::getUniqueConstraintDeclarationSQL()`