In some use cases, some site level docs are only included in specific
manifests. This is so sites can call out what they want deployed, however
currently Armada is checking for all documents to exist and leads
to an invalid manifest exception.
This PS removes the '.build_charts_deps()' and 'build_chart_groups()' calls
in 'get_manifest()' so that only chart documents, and chart group documents
are built after finding them within 'build_armada_manfiest()' and
'build_chart_group()'. 'build_armada_manifest()' will now throw the
related 'Could not find chart group... exception' for related chart
and chart group issues. Additional subclass exceptions were added along
with adding traceback to capture the chained exceptions.
Change-Id: Idc8a75b290ac0afb1e177203535b012d589b708f
cb57588968