refactor: 💡 Update choose a provider translations

Update choose a provider translations to concat provider specific text
when appropriate

✅ Closes: ICU-3529

addons/core/translations/en-us.yaml

@@ -40,6 +40,7 @@ descriptions:
   neither-list-nor-create: You do not have permission to list or create {resource}.
   no-results: We found no matching records.
   choose-a-provider: There are several built-in plugins for the most common providers. You can choose from on of the included plugins or use a custom plugin.
+  choose-a-provider-azure: Boundary does not yet support rotating credentials.
   provider: This is the provider for this host catalog. The format of the host set filters are specific to each provider.
 questions:
   delete-confirm: Are you sure you want to delete this resource?

addons/core/translations/resources/en-us.yaml

@@ -97,10 +97,6 @@ host-catalog:
     azure_client_id:
       label: Client ID
       help: The client ID for the client you want Boundary to use.
-    azure_choose_a_provider:
-      description: There are several built-in plugins for the most common providers. You can choose from on of the included plugins or use a custom plugin. Boundary does not yet support rotating credentials.
-    aws_choose_a_provider:
-      description: There are several built-in plugins for the most common providers. You can choose from on of the included plugins or use a custom plugin.
 host-set:
   title: Host Set
   title_plural: Host Sets

ui/admin/app/components/form/host-catalog/aws/index.hbs

@@ -77,9 +77,7 @@
 
     <form.fieldset>
       <:title>{{t 'titles.choose-a-provider'}}</:title>
-      <:description>
-        {{t 'resources.host-catalog.form.aws_choose_a_provider.description'}}
-      </:description>
+      <:description>{{t 'descriptions.choose-a-provider'}}</:description>
 
       <:body>
         <form.radioGroup

ui/admin/app/components/form/host-catalog/azure/index.hbs

@@ -77,7 +77,11 @@
     <form.fieldset>
       <:title>{{t 'titles.choose-a-provider'}}</:title>
       <:description>
-        {{t 'resources.host-catalog.form.azure_choose_a_provider.description'}}
+        {{concat
+          (t 'descriptions.choose-a-provider')
+          ' '
+          (t 'descriptions.choose-a-provider-azure')
+        }}
       </:description>
 
       <:body>