Add web console for creating registrars

This console is only to be used by Admins (either GAE admins for this project, or Support accounts). It is for "internal" use only, not for use by the registrars themselves.

To prevent abuse, the registrar is created in a non-functional PENDING state and can only be made functional from the nomulus shell tool.

While in "PENDING" state, the registrar can be updated from the registrar-console by admins.

Also - moving all the web consoles to the same directory (moving the otesetup/* files into registrar/)

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=229681011

java/google/registry/config/RegistryConfig.java

@@ -1381,6 +1381,14 @@ public final class RegistryConfig {
       }
     }
 
+    /** Returns a singleton random string generator that uses digits only. */
+    @Singleton
+    @Provides
+    @Config("digitOnlyStringGenerator")
+    public static StringGenerator provideDigitsOnlyStringGenerator(SecureRandom secureRandom) {
+      return new RandomStringGenerator(StringGenerator.Alphabets.DIGITS_ONLY, secureRandom);
+    }
+
     /** Returns a singleton random string generator using Base58 encoding. */
     @Singleton
     @Provides