[Feature Request] Global override for `disable_column_statistics`

[maederm]

The new mariadb offering in cloud foundry doesn't support column statistics at all.
I'd like to have the possibility of disabling this feature also for dynamically discovered databases (e.g. the ones not specified in BACKMAN_CONFIG.

Implementation idea

Create a new global config called default_disable_column_statistics that has the default value of false. If it is set to true all service instances that don't have disable_column_statistics set explicitly should be set to true.

Alternative approaches

• Set disable_column_statistics by default to true
• Use mariadb-dump instead of mysqldump => This should solve the problem without having to care about column statistics at all