Improve Layout of ContactEdit

[b-erhart]

I thought the current ContactEdit screen looks a bit messy, since the alignments and margins were a bit off in some places. So I tried to improve the situation a little.

This is a short summary of the changes I made:

• Use Grid-based layout
• Change TextField placeholder attributes to label so the name is still visible after input
• Switch TextField variants from standard to outlined for a more modern look and more even looking spacing
• Add icons for better orientation
• Add button to show/hide name fields that are rarely used. Fields that have content are never hidden

Obviously, design stuff is a pretty subjective thing. So I'm not sure if you like this kind of layout or if this is the design direction you want to go in. This is simply a suggestion and I am happy to make adjustments.

Here is a small comparison: Before:

After:

[b-erhart]

Also, I tried to follow the general style of the existing code. But since this is my first PR here, I'm not sure if I managed to do that everywhere. Please tell me if something doesn't fit and I will change it.

[tasn]

Oh, why did you close it? Sorry I missed it until now. Want me to take a look?