[goecharger] Add transaction api key

[cribskip]

This PR fixes #13104 and adds the transaction / trx api key to the binding.

[cribskip]

As, crap, is there a way to fix the wrong sign-off-messages in the commits other than staring all over? Thanks :-)

[lolodomo]

Try squashing all your commits in one and then add the proper "Signed-off-by" entry to the tesulting commit.

[jlaur]

@cribskip - see third chapter here: https://git-scm.com/book/en/v2/Git-Tools-Rewriting-History

[lolodomo]

@jlaur : I let you merge when you like.