Addition of update activity distribution by alias, minor correction (#11905)

* Addition of update activity distribution by alias, minor correction

* Distribute Update activity after adding alias
* Add uniqueness verification to alias uri
* accept acct starting with @

* fix double-quoted to single-quoted

app/models/account_alias.rb

@@ -17,11 +17,17 @@ class AccountAlias < ApplicationRecord
 
   validates :acct, presence: true, domain: { acct: true }
   validates :uri, presence: true
+  validates :uri, uniqueness: { scope: :account_id }
 
   before_validation :set_uri
   after_create :add_to_account
   after_destroy :remove_from_account
 
+  def acct=(val)
+    val = val.to_s.strip
+    super(val.start_with?('@') ? val[1..-1] : val)
+  end
+
   private
 
   def set_uri