Update kuttl tests for Postgres 15 public schema updates

With Postgres 15, the removal of PUBLIC creation permisson on the
public schema requires updates to our kuttl test logic. This
commit allows the tests to perform as expected with these new
changes by creating/referencing new schemas as needed. Note that
these changes should not impact Postgres versions < 15.

Issue: [sc-16289]

Author: tjmoore4

testing/kuttl/e2e/pgbackrest-restore/02--create-data.yaml

@@ -28,4 +28,5 @@ spec:
             - --set=ON_ERROR_STOP=1
             - --command
             - |
+              CREATE SCHEMA "original";
               CREATE TABLE important (data) AS VALUES ('treasure');

testing/kuttl/e2e/pgbackrest-restore/14--lose-data.yaml

@@ -21,7 +21,7 @@ commands:
       # A reason to restore. Wait for the change to be sent to the WAL archive.
       kubectl exec --namespace "${NAMESPACE}" "${PRIMARY}" \
         -- psql -qb original --set ON_ERROR_STOP=1 \
-          --command 'DROP TABLE important' \
+          --command 'DROP TABLE original.important' \
           --command "SELECT pg_stat_reset_shared('archiver')" \
           --command 'SELECT pg_switch_wal()'
 

testing/kuttl/e2e/streaming-standby/02--create-data.yaml

@@ -28,4 +28,5 @@ spec:
             - --set=ON_ERROR_STOP=1
             - --command
             - |
+              CREATE SCHEMA "primary-cluster";
               CREATE TABLE important (data) AS VALUES ('treasure');