fix: remove right padding when a label contains HTML entities

[leon19]

📑 Summary

Decode the HTML entities from the label text before adding them to the
HTML this prevents a miss-calculation of the label text length

Example

stateDiagram-v2
[*] --> 1
1 --> 2: test({ foo#colon; 'far' })
2 --> [*]

Before

After

📏 Design Decisions

Not applicable

📋 Tasks

Make sure you

• 📖 have read the contribution guidelines
• 💻 have added unit/e2e tests (if appropriate)
• 🔖 targeted develop branch

[knsv]

Thanks @leon19 !