Scala examples refactor

[L-Lavigne]

This PR refactors the Scala examples, in preparation for eventually aligning all Scala and Java examples with their Kotlin counterparts.

Summary of changes:

• Consolidated similar Scala examples together and re-organized their package structure to better express their purpose.
• Refactored the Scala examples to use a more concise, more idiomatic Scala 3 style.
• Partly re-wrote the Scala readme, which was referencing outdated ai and AIScope constructs.
• Moved some Scala classes from the conversation to the serialization package and cleaned up the code a bit.
• Added convenience overloads of all prompt methods that take a String instead of a Prompt object.
• Applied minor grammar/syntax fixes in Scala-related code and docs.

Note: I don't have a SerpAPI access token so I was unable to fully test the examples that rely on this. (I did group them in a context.serpapi subpackage and added a note in the Readme about the token requirement). If anyone has a token available and can help with testing these please let me know.

[raulraja]

This looks awesome @L-Lavigne , thank you for looking into it.
Now that I recall our previous conversations I'm wondering if Xef is usable inside Minecraft!. 🍻

[L-Lavigne]

This looks awesome @L-Lavigne , thank you for looking into it. Now that I recall our previous conversations I'm wondering if Xef is usable inside Minecraft!. 🍻

Thanks @raulraja , it'll be good to work with you and @juanpedromoreno again! Maybe I'm going to add a Minecraft-related example or two. :-D

Are we good to merge or do we need another approver?