Allow custom query parameters on menu items

[fenz85]

On menu items there's the option to add query parameters that add data to the URL, however the way this is formatted does not match what different websites expect and work with.

For example, we can send https://yoursite.com?contact_email=joe.bloggs@contoso.com but the website may expect https://yoursite.com?email=joe.bloggs@contoso.com instead. Ideally this should be customisable.

[Leeroy-Steele]

+1 Pablo is requestion the same feature - #547330