Add user management

[SangMinhTruong]

ELCA_SMARTDATALAKE-260

[SangMinhTruong]

Looks good to me, I just have two things to add/change:

1. If I click on "Settings" I go back to the main screen, but the directory of Settings is still displayed. Here it would make sense to go to the page of the first entry in die Settings directory. In this case, the "User Management".

2. If I do not have the permission to change any user settings, the options to modify, add or delete a user are greyed out. Here, it would be nice to have a Title, which appears if you hover with the mouse over an icon. This Title could explain, that the user does not have the appropriated rights to modify any user permission.

New changes are included in the new commits, please have a look! Remarks:

• As discussed, I have also updated these labels to "User Management" for consistency
• However, for the Breadcrumbs (marked in 'orange'), there is not a straight-forward way to change it for now. The Breadcrumbs are constructed using the url (first segment is capitalized). So changing a segment to a specific text will require rewrite of the Breadcrumbs component. This is outside of scope for this ticket IMO.