Replace loadByUniqueId() with methods that don't overload unique id

It is replaced by loadByForeignKey(), which does the same thing that
loadByUniqueId() did for contacts, hosts, and domains, and also
loadDomainApplication(), which loads domain application by ROID. This eliminates
the ugly mode-switching of attemping to load by other foreign key or ROID.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=133980156

javatests/google/registry/flows/domain/DomainAllocateFlowTest.java

@@ -16,7 +16,7 @@ package google.registry.flows.domain;
 
 import static com.google.common.io.BaseEncoding.base16;
 import static com.google.common.truth.Truth.assertThat;
-import static google.registry.model.EppResourceUtils.loadByUniqueId;
+import static google.registry.model.EppResourceUtils.loadDomainApplication;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.testing.DatastoreHelper.assertBillingEvents;
 import static google.registry.testing.DatastoreHelper.createTld;
@@ -132,7 +132,7 @@ public class DomainAllocateFlowTest
         UserPrivileges.SUPERUSER,
         readFile("domain_allocate_response.xml"));
     // Check that the domain was created and persisted with a history entry.
-    DomainResource domain = reloadResourceByUniqueId();
+    DomainResource domain = reloadResourceByForeignKey();
     assertAboutDomains().that(domain)
         .hasOnlyOneHistoryEntryWhich()
         .hasType(HistoryEntry.Type.DOMAIN_ALLOCATE);
@@ -142,8 +142,7 @@ public class DomainAllocateFlowTest
     boolean sunrushAddGracePeriod = (nameservers == 0);
 
     // The application should be marked as allocated, with a new history entry.
-    DomainApplication application =
-        loadByUniqueId(DomainApplication.class, applicationId, clock.nowUtc());
+    DomainApplication application = loadDomainApplication(applicationId, clock.nowUtc());
     assertAboutApplications().that(application)
         .hasApplicationStatus(ApplicationStatus.ALLOCATED).and()
         .hasHistoryEntryAtIndex(1)
@@ -284,7 +283,7 @@ public class DomainAllocateFlowTest
     setupDomainApplication("tld", TldState.QUIET_PERIOD);
     setEppInput("domain_allocate_dsdata.xml");
     doSuccessfulTest(2);
-    assertAboutDomains().that(reloadResourceByUniqueId())
+    assertAboutDomains().that(reloadResourceByForeignKey())
         .hasExactlyDsData(DelegationSignerData.create(
               12345, 3, 1, base16().decode("49FD46E6C4B45C55D4AC")));
   }
@@ -295,7 +294,7 @@ public class DomainAllocateFlowTest
     setEppInput("domain_allocate_dsdata_8_records.xml");
     doSuccessfulTest(2);
     assertThat(getOnlyGlobalResource(DomainResource.class)).isNotNull();
-    assertThat(reloadResourceByUniqueId().getDsData()).hasSize(8);
+    assertThat(reloadResourceByForeignKey().getDsData()).hasSize(8);
   }
 
   @Test
@@ -326,7 +325,7 @@ public class DomainAllocateFlowTest
     String expectedCsv = String.format(
         "%s,example-one.tld,370d0b7c9223372036854775807,1,"
         + "2010-09-16T10:00:00.000Z,2010-07-16T09:00:00.000Z,2010-08-16T10:00:00.000Z",
-        reloadResourceByUniqueId().getRepoId());
+        reloadResourceByForeignKey().getRepoId());
     assertTasksEnqueued(
         "lordn-claims", new TaskMatcher().payload(expectedCsv).tag("tld"));
   }
@@ -339,7 +338,7 @@ public class DomainAllocateFlowTest
     String expectedCsv = String.format(
         "%s,example-one.tld,370d0b7c9223372036854775807,1,"
         + "2011-08-17T09:00:00.000Z,2010-07-16T09:00:00.000Z,2010-08-16T10:00:00.000Z",
-        reloadResourceByUniqueId().getRepoId());
+        reloadResourceByForeignKey().getRepoId());
     assertTasksEnqueued("lordn-claims", new TaskMatcher().payload(expectedCsv).tag("tld"));
   }