Update Client Certificate test to cover all scenarios

[Gunni]

Current setup has Client Certificate always optional.

I suggest supporting the following:

Server setting	User Sends Cert	Result	Comment
Feature disabled	No	Loads	Normal HTTPS, skip this
Feature disabled	Any cert	Loads	Normal HTTPS, skip this
----------------------	-----------------	--------------------------------	--------------------------------------
Optional	No cert	Loads with error page	Page comments that cert is missing
Optional	Expired cert	Loads with error page	Page comments that cert is expired
Optional	Valid cert	Green page, showing cert info?	GREEN page
----------------------	-----------------	--------------------------------	--------------------------------------
Required	No cert	TLS handshake error	Not possible to finish handshake
Required	Expired cert	TLS handshake error	Not possible to finish handshake
Required	Valid cert	Green page, showing cert info?	GREEN page