Changed bossbar title to TextComponent instead of String

[leobeg]

Description

This PR migrates from the String implementation to the Vanilla TextComponent

Testing

Open up the game and use /bossbar add minecraft:test {"text":"Pumpkin","color":"gold"}
Use /bossbar set minecraft:test players @a
You should now see the colored bossbar

Checklist

Things need to be done before this Pull Request can be merged.

• Code is well-formatted and adheres to project style guidelines: cargo fmt
• Code does not produce any clippy warnings: cargo clippy
• All unit tests pass: cargo test
• I added new unit tests, so other people don't accidentally break my code by changing other parts of the codebase. How?

[Snowiiii]

Looks good, I have nothing to complain about. Thank you @leobeg 👍. Now we can have cool Colors and more 🌈