fix: unknown listener type: undefined

[jeroen-huizer-conclusion]

Pull request type

Bug fix (non-breaking change which fixes an issue)

---

Description

Using LeafletMap, when locations are configured to have both a title and an onclick action, the browser console would log a warning: unknown listener type: undefined. For us this was quite annoying because we render 100's of locations.

I resolved this by not adding eventhandlers to the marker when the location has a title.
I'm not sure whether GoogleMap also has this issue.

What should be covered while testing?

• When a location does not have a title and does not have an onclick action: clicking should do nothing
• When a location has a title, but not an onclick: clicking should open a popup
• When a location does not have a title, but does have an onclick: clicking the location should execute the onclick action
• When a location has a title and an onclick action: clicking should open a popup, clicking the popup should execute the action