feat: multiple domains (#188)

* check uniqueness on create and register user

* change user email, reserve release unique email

* usergrant unique aggregate

* usergrant uniqueness

* validate UserGrant

* fix tests

* domain is set on username in all orgs

* domain in admin

* org domain sql

* zitadel domain org name

* org domains

* org iam policy

* default org iam policy

* SETUP

* load login names

* login by login name

* login name

* fix: merge master

* fix: merge master

* Update internal/user/repository/eventsourcing/user.go

Co-authored-by: Livio Amstutz <livio.a@gmail.com>

* fix: fix unique domains

* fix: rename env variable

Co-authored-by: adlerhurst <silvan.reusser@gmail.com>
Co-authored-by: Livio Amstutz <livio.a@gmail.com>

internal/login/static/templates/login.html

@@ -1,3 +1,4 @@
+
 {{template "main-top" .}}
 
 <h1>{{t "Login.Title"}}</h1>
@@ -9,8 +10,8 @@
 
     <div class="fields">
         <div class="field">
-            <label class="label" for="username">{{t "Login.Username"}}</label>
-            <input class="input" type="text" id="username" name="username"  value="{{ .UserName }}" autocomplete="username" autofocus required>
+            <label class="label" for="username">{{t "Login.Loginname"}}</label>
+            <input class="input" type="text" id="username" name="username" placeholder="{{t "Login.LoginnamePlaceHolder"}}" value="{{ .UserName }}" autocomplete="username" autofocus required>
         </div>
     </div>