Write UI Test for HealthCheck use

[maybeec]

Write one SWTBot UI test for the HealthCheck use which has been left out in PR #385.

Testdata:

• context configuration with two linked templates configurations. All not up-to-date.

Testworkflow:

1. trigger health check - check message that context config has to be updated
2. trigger upgrade of context config - check message after upgrade
3. trigger each templates config upgrade - check message after upgrades

[changecreator]

Currently checking out how to perform a SWTBot UI test.

[maybeec]

@erikgruener please check the following and probably fix it can be reproduced:

modify the context.xml to an invalid state. Click generate, so cobigen will say, that the configuration is not valid, but you can start the healthcheck. So click on the healthcheck button within the error message. For me it was showing, that everything is fine, which is crazy as the the context.xml obviously could not be parsed.

[maybeec]

Fixed by #1100