refactor: add test cases for vertex resource and update api with put and replace

[pollend]

refactored vertex resource with updated javadocs, more tests and tried to make test cases more consistent

• replaced copyBuffer with replace
  • this will replace the contents of a buffer with the target one
• introduced put commend
  • will take a bytebuffer or buffered resource and append it to the existing.

[Cervator]

Looks fine, as far as I can tell, even if I can't say I necessarily get any of it - but this is likely to not get such detailed review anyway these days, so merging anyway. Tests pass (yay more tests and doc), game runs 👍