Create MultipleUpdateHandler for implementations that use PreparedStatements

[GLaDAP]

Implementations that use Prepared Statements right now implement the operation handling within the class that extends the BaseDb. However, to separate the functionality and clarify the code, it is better to move the execution of the queries to a separate handler. Some difficulties arise:

• The prepared statements are created differently
• Separate update queries require parameters that are not yet present in the parameter maps or have different positions

Example implementation is the Postgres implementation. Related issue is #265, when implemented, also uses prepared statements in multiple updates.