Database refactoring 2024-08

[axel-wild]

The database schema is to be further developed more independently of the ASV-DB schema in the future. The DB only needs to cover one school year and can be opened up to other data sources through restructuring.

In the first step, the table egw_schulmanager_asv_unterrichtselement is replaced by the table egw_schulmanager_asv_unterrichtselement2.

[axel-wild]

TODO (because of depending changes):

• open in document in class-view fails
• display contact view from context menu fails

class view is loading slowly