Support disabling sql_generate_invisible_primary_key via MySQL configuration entry (resolves MySQL 8.x issue as reported by REDCap database checks)

[epopisces]

As reported in the REDCap Community forums, building REDCap from scratch when using the latest 8.x version of MySQL is (sporadically) resulting in the following error:
YOUR REDCAP DATABASE STRUCTURE IS INCORRECT

The solution is to set the sql_generate_invisible_primary_key value on the MySQL flexible server to 'OFF' prior to running the REDCap install script for the database.

Via Terraform these could be implemented via an azurerm_mysql_flexible_server_configuration resource:

resource "azurerm_mysql_flexible_server_configuration" "disable_invisible_primary_key" {
  resource_group_name = azurerm_resource_group.redcap.name
  server_name         = azurerm_mysql_flexible_server.redcap.name
  name                = "sql_generate_invisible_primary_key"
  value               = "OFF"
}

I have not yet tested whether this has an impact when using prior version of MySQL: if so it could include a count = startswith(var.mysqlVersion, "8") ? 1 : 0. Or even better such a conditional used in a locals block should add a map an argument to a merge() function such as suggested in #50 (preferred).

[SvenAelterman]

This has been resolved in the Bicep code. It does not work with SQL versions prior to 8.0.30.