Interesting. TIL, because so far I thought that there was not even a name for this plant in English (except for the Latin scientific name).

So far, I've only seen this flavour to be used in German speaking countries.

Waldmeister is it's own unique flavour, comparable to menthol (mint) but different, used mostly for sweets/drinks. Quick googling shows that it's not known in US as a flavouring.
Sold Foodstuffs usually contain a artifical flavour from a cumarin derivative that is safer.

Any relation to beso?

Interesting, because I think the etymology of "pussy" for a cat in English is from the pspsps sound which is a bit like a kissing sound