Refactor/admin single user view

[CodeNamedRobin]

Description

Refactors the single user view for admins. Refactors the user edit form to use the new form implementation, and clears up a lot of functional code in the main component, moving it to separate components. Below is what the page looks like now.

Related issues/external references

One of many #273
One of many #228 (admin single user view having functional code)
One of many #228 (removing changeinfocomponent)

Types of changes

• New feature (non-breaking change which adds functionality)
• Style (Change that do not affect the functionality of the code)

[JustSamuel]

Please add screenshots highlight your changes :(

[SuperVK]

Nickname should be able to be null right?

Some translations missing as well. (Header, confirm message)

(bit irrelevant for here cause the backend allows it) Are we allowed to change the names of members account from GEWIS?

[SuperVK]

Nickname cannot be null is still an issue, to replicate:

1. click on edit
2. click on username
3. de-focus the username field
4. voila

[CodeNamedRobin]

Nickname cannot be null is still an issue, to replicate:

1. click on edit

2. click on username

3. de-focus the username field

4. voila

This has been fixed in the latest commit.