Fix various minor frontend issues
# Bug Report
This ticket serves as a collection of minor frontend issues to be fixed before the frontend is handed over.
## :bug: List of frontend issues
#### ~~Create Semantic Repository Dialog~~
- Missing explanatory text field for 'mandatory' input fields in [Create new semantic repository dialog](https://nuxtend.desh.dev.xitaso.com/configuration#semanticrepositories)
- adjust white space between input fields
- adjust dialog width to the smaller instance (like create collection)
#### ~~Add User Group Dialog~~
- Missing 'required field' star/ symbol in [Add user group dialog](https://nuxtend.desh.dev.xitaso.com/configuration#userGroups)
- adjust white space between input fields
- adjust dialog width to the smaller instance (like create collection)
#### ~~User group Detail~~ - DONE ???
* align "ID" with the other items on this screen
#### ~~Date Format~~ - DONE ???
- there is one location in the frontend that displays a German date format (in the timeseries reference detail view: intervall) - keep that consistent to rest of app

#### ~~Semantic Annotations~~
- While semantic annotations are loading no loading spinner is displayed
This could be confusing because a user could incorrectly assume that no semantic annotations exists even though they are still being queried
Most components are replaced with a spinner when no data is currently available so this is also a consistency matter.
#### ~~Time Series Container Detail View~~ - DONE ???
- in this table a line can be expanded to show the semantic annotations. When hovering over the expanded line both the expanded line and the line in the table should be the hover-blue
#### ~~Graph and Metrics Dialog in Time Series Reference View~~
#### - DONE ???
- In the metrics dialog, the index colors form the metrics does not match the associated graph color (as seen in the review; can we confirm?)
#### ~~Tab Titles~~ - DONE
- Tab titles for collections and containers shall display name | shepard.
#### ~~Black in Dark Mode Drop Downs~~ - ???
* user groups: permission
* create new container: type, permission
* maybe others?
#### ~~Subheadlines in Create/Edit Collection/Data Object~~ - DONE ???
* Adjust spacing after headline to make consistent
issue