Class Diagram: Adjust spacing of newly added lines to a class

[farisd16]

Checklist

• [ ] I documented the TypeScript code using JSDoc style.
• I added multiple screenshots/screencasts of my UI changes
• [ ] I translated all the newly inserted strings into German and English

Motivation and Context

Fixes #333

Description

I have adjusted the height of newly added lines to a class to match the height of lines from the preview (specifically class-preview.ts)

Steps for Testing

1. Create a class diagram
2. Add a new class
3. Add new lines (attribute, method, etc.) to the class
4. Assert that all lines have even spacing

Test Coverage

| File | Branch | Line |
| uml-classifier-member.ts | 100% | 100% |

Screenshots

Before:

After:

[FelixTJDietrich]

@farisd16 it is maybe a bit too much space now? Can you make it similar to Constant 4, Constant 5, Constant 6 in the before screenshot?

[farisd16]

@farisd16 it is maybe a bit too much space now? Can you make it similar to Constant 4, Constant 5, Constant 6 in the before screenshot?

Sure, this is what it looks like:

[FelixTJDietrich]

Somehow the vertical padding is now smaller, don't you think?

[FelixTJDietrich]

Code changes look good to me and I could verify that the spacing looks correct now locally :)

[loreanvictor]

code looks good to me too, though I wonder if we need to manage these visual constants a bit better (perhaps in a follow-up issue).