Have nicer result failure messages

[carl-baillargeon]

Would be nice to have a more human readable format for the test result failures messages:

BGP tests are also not very user friendly:

Could be related to #427

[carl-baillargeon]

Adding VerifySnmpContact to the list:

[carl-baillargeon]

@vitthalmagadum Will tackle the interfaces, LLDP, hardware tests.
@carl-baillargeon Will tackle the BGP tests.

[carl-baillargeon]

Some tests failure messages will be improved as part of #388