Document StatusValue better and add per-resource restrictions

This generalizes the "LINKED can't be anywhere" idea into more
targeted restrictions.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=146158204

javatests/google/registry/tools/GenerateEscrowDepositCommandTest.java

@@ -204,9 +204,7 @@ public class GenerateEscrowDepositCommandTest
         .setLastTransferTime(DateTime.parse("1910-01-01T00:00:00Z"))
         .setLastEppUpdateClientId("CeilingCat")
         .setLastEppUpdateTime(clock.nowUtc())
-        .setStatusValues(ImmutableSet.of(
-            StatusValue.OK,
-            StatusValue.PENDING_UPDATE))
+        .setStatusValues(ImmutableSet.of(StatusValue.OK))
         .build();
   }