[Feature] Quality of live improvements and bugfixes

## Description

During roll-out / pilots we found several issues we need to fix to make the software more usable

## Hints / Details

### Work Package Breakown

Prio 1:

- [x] #979
- [x] #981
- [x] #982
- [x] #991

> [!note]
> #981 has been moved outside as it's an own feature

Prio 2:

- [x] #985
- [x] #977
- [x] #978
- [x] #980
- [x] #983

Prio 3:

- [x] #1064

> [!note]
> The following stories has been made a feature due to their complexity:
>
> - #1045 ([Story] Allow to select sites who stock or produce materials for own partner)
> - #1046 ([Story] Introduce concept to handle old data)
>

## Outcome / Acceptance Criteria

### Outcome

### Acceptance Criteria

## Out of Scope

- Ensure that we can cope with the scenario that the same submodels are provided by another application.