[Feature request] Add function get_element_html(bid)

[kripper]

Plase add a new function in functions.py to return the HTML of a element identified by its bid.

This is for All-Hands-AI/OpenHands#5727 (comment)

[gasse]

Hi @kripper. You should be able to recover an element's HTML from its BID by post-processing the obs returned at every step. If you really need to have this as an action it can be done as well, we'd gladly add it to browsergym. The team doesn't have much bandwidth at the moment though and this is not a priority feature we'll be working on. I would encourage you to send us a pull request, community contributions are welcome :)