feat: Support inheritance for body

[tienvx]

This feature is useful for implementing compatibility suite.

[JP-Ellis]

I suspect it is my lack of understanding of PHP, but at least to me, the use of a match (true) is confusing.

Would it not be clearer to have:

if ($body instanceof Bytes) { ... }
else if ($body instance of Text) { ... }
// ...
else {
  throw new InteractionBodyNotAddedException();
}

Then again, if the match (true) pattern is common for PHP, then I'm happy to approve it.

[tienvx]

There are 3 ways of doing this:

• if/elseif/else
• switch (true)
• match (true)

The reason is very simple: I personally prefer match (true) because it's new feature from PHP 8, and it's shorter than switch (true). I personally don't like using if/elseif/else in this case.

[JP-Ellis]

Thanks for explaining this! Indeed it was my misunderstanding of PHP.