Clarify optional vs. required fields

Added a separator between the fields, and marked required fields as "required", so you can't submit without them

Also - changed from base64 to base58 in for the auto-generated password. It's conceivable that someone might need to read it outloud to someone else - and not having "visually similar" characters (like O and 0) can be helpful.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=228810158

java/google/registry/ui/soy/Forms.soy

@@ -107,6 +107,7 @@
 {template .inputFieldValue}
   {@param name: string}
   {@param? readonly: bool}
+  {@param? required: bool}
   {@param? value: ?}
   {@param? namePrefix: string}
   {@param? placeholder: string}
@@ -119,6 +120,7 @@
          {if isNonnull($placeholder) and not $readonly}
          placeholder="{$placeholder}"
          {/if}
+         {if $required}required{/if}
          {if $readonly}readonly{/if}>
 {/template}
 
@@ -128,6 +130,7 @@
   {@param label: string}
   {@param name: string}
   {@param? readonly: bool}
+  {@param? required: bool}
   {@param? namePrefix: string}
   {@param? value: ?}
   {@param? description: string}

java/google/registry/ui/soy/otesetup/Console.soy

@@ -113,7 +113,7 @@
             {param name: 'clientId' /}
             {param value: $baseClientId /}
             {param placeholder: 'registrar\'s ID' /}
-            {param readonly: false /}
+            {param required: true /}
           {/call}
           <span class="{css('description')}">
             Must:
@@ -136,16 +136,22 @@
         {param description kind="text"}
           Will be granted web-console access to the OTE registrars.
         {/param}
-        {param readonly: false /}
+        {param required: true /}
       {/call}
+      <tr>
+        <td colspan="2">
+          <hr>
+          <h1>Optional fields</h1>
+          Don't fill unless you have a good reason to.
+        </td>
+      </tr>
       {call registry.soy.forms.inputFieldRowWithValue}
-        {param label: 'Password (optional)' /}
+        {param label: 'EPP password' /}
         {param name: 'password' /}
-        {param placeholder: 'Optional password' /}
+        {param placeholder: 'Optional' /}
         {param description kind="text"}
-          The password used to for EPP login. Leave blank to auto-generate a password.
+          The password used to for EPP login. Leave blank to auto-generate.
         {/param}
-        {param readonly: false /}
       {/call}
       {call registry.soy.forms.submitRow}
         {param label: 'create' /}