Fully qualify project configuration names

The layout stores the configuration of a project in the ProjectConfig
class (not the Project class -- that represents the abstract idea
of a project independent of Zuul, the ProjectConfig represents a
particular Zuul configuration operating on that project).  Therefore,
in the continuing effort to fully qualify project names, index
ProjectConfig objects by their canonical project name.  Use that
name when looking for a ProjectConfig to find the jobs to run for
a given change.

Story: 2000953
Change-Id: I733a66369c969770e57c2fa8b30822bd15e1aca7
diff --git a/tests/fixtures/config/duplicate-pipeline/main.yaml b/tests/fixtures/config/duplicate-pipeline/main.yaml
index ba2d8f5..5e1bc6e 100755
--- a/tests/fixtures/config/duplicate-pipeline/main.yaml
+++ b/tests/fixtures/config/duplicate-pipeline/main.yaml
@@ -4,3 +4,5 @@
       gerrit:
         config-repos:
           - common-config
+        project-repos:
+          - org/project