FR: configure extra parameters for browser

[jkatnik]

Context: on my laptop, I use two different Chrome profiles - one for private usage, and a second for professional.

It is possible to select a profile while starting the browser like this:
google-chrome --profile-directory="Profile 2"
Firefox, Opera and Brave have similar functionality

Problem:
When I click on the link in Guake, it probably calls xdg-open, which in turn opens the link in the last recently focused browser window. Which in my case Is not always the right choice. I'd like to have control over which profile is selected.

Proposed Solution: Allow configuration of the Guake browser binary file and its parameters in the settings.

Here is how it looks in webapp-manager.