ui: Hide create buttons for policies/roles/namespaces with readonly access (#10914)

This PR adds a check to policy, role and namespace list pages to make sure the user has can write those things before offering to create them via a button. (The create page/form would then be a read-only form)

.changelog/10914.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+ui: hide create button for policies/roles/namespace if users token has no write permissions to those areas
+```

ui/packages/consul-ui/app/templates/dc/acls/policies/index.hbs

@@ -69,7 +69,9 @@ as |route|>
         </h1>
       </BlockSlot>
       <BlockSlot @name="actions">
+  {{#if (can "create policies")}}
           <a data-test-create href="{{href-to 'dc.acls.policies.create'}}" class="type-create">Create</a>
+  {{/if}}
       </BlockSlot>
       <BlockSlot @name="toolbar">
       {{#if (gt items.length 0) }}

ui/packages/consul-ui/app/templates/dc/acls/roles/index.hbs

@@ -63,7 +63,9 @@ as |route|>
         </h1>
       </BlockSlot>
       <BlockSlot @name="actions">
+  {{#if (can "create roles")}}
         <a data-test-create href="{{href-to 'dc.acls.roles.create'}}" class="type-create">Create</a>
+  {{/if}}
       </BlockSlot>
       <BlockSlot @name="toolbar">
       {{#if (gt items.length 0) }}

ui/packages/consul-ui/app/templates/dc/nspaces/index.hbs

@@ -55,7 +55,9 @@ as |route|>
         </h1>
       </BlockSlot>
       <BlockSlot @name="actions">
+  {{#if (can "create nspaces")}}
           <a data-test-create href="{{href-to 'dc.nspaces.create'}}" class="type-create">Create</a>
+  {{/if}}
       </BlockSlot>
       <BlockSlot @name="toolbar">
       {{#if (gt items.length 0)}}