Add command for eval and tap sexp at point

[lambdank]

This request is a bit related to #3094, where the issue creator wants to be able to tap> every form that is evaluated.
In my workflow, I only use tap> when I need to inspect a large or complex piece of data (in portal or something similar).
Therefore, I propose a command that evaluates the sexp-at-point and taps the result.

I don't know whether such a feature is general enough to be an enhancement, or whether it should live in my own config.
I've found a simple solution, that seems to work for me and I'll open a related merge request.
Feel free to reject it, if it's too niche.