Remove eager call on CommandLineWithOutputValue for BuildScan output

[cdsap]

Build Scan output invalidated the configuration cache because of an eager call on the ValueSource:

Calculating task graph as configuration cache cannot be reused because a build logic input of type 
'CommandLineWithOutputValue' has changed.

Issue #6.

This was caused by the following:

ConsolidateProcesses().consolidate(project.jStat().get(), project.jInfo().get())

Moved the provider call in the BuildScanExtension block.

Added unit test in CI to test the BuildScan output(requires environment variables GE_URL and GE_API_KEY).