New Browser to skip if exists and switch

[mkorpela]

Is your feature request related to a problem? Please describe.

New Context by default either attaches to existing browser or creates a one with default options. For several cases default options are not good enough. For instance a headfull browser might be needed or a firefox.

add an option to skip and switch to New Browser that can find the right default browser for you.

[mkorpela]

https://github.com/MarketSquare/robotframework-browser/pull/1318

[Snooz82]

New Implementation done. Fixed By #2626