Fixes the following issues:

• Previously the collector failed with a conflict error, now we re-queue that reconcile attempt, I have tracked and confirmed that eventually the conflicting reconcile succeeds.
• Added a minimal config-check, that we might get rid of later, but it's a good-enough start IMO, partially fixes: If no tenant is assigned to a controller a wrong config is generated #22
  NOTE: I will do a follow-up PR and come up with a better config-check
• Noticed that we could panic if a Bridge had either no source or target tenant... Fixed.
• We are logging errors on the first reconciliation #63
• Upon introducing Bridges, we opened up the possibility to have a Tenant with either no subs or logsource-ns's, but It wasn't possible before.

Topology differences:

BEFORE
AFTER