New hooks for admin page, for head, body, and before_page

+move LOGIN_POST to correct place

system/templates/admin.login.html.twig

@@ -25,7 +25,7 @@
 						</div>
 						<input type="text" class="form-control" id="account-name-input" name="account_login" placeholder="{{ account_login_by }}" required autofocus>
 					</div>
-
+					{{ hook('HOOK_ADMIN_LOGIN_AFTER_ACCOUNT') }}
 					<div class="input-group mb-3">
 						<div class="input-group-prepend">
 							<span class="input-group-text"><i class="fa fa-key"></i></span>
@@ -33,6 +33,7 @@
 						<input type="password" class="form-control" placeholder="Password" name="password_login"
 							   placeholder="Password" required>
 					</div>
+					{{ hook('HOOK_ADMIN_LOGIN_AFTER_PASSWORD') }}
 					<div class="row">
 						<div class="col-8">
 							<div class="icheck-primary">
@@ -45,6 +46,7 @@
 							<button type="submit" class="btn btn-info btn-block">Sign In</button>
 						</div>
 					</div>
+					{{ hook('HOOK_ADMIN_LOGIN_AFTER_SIGN_IN') }}
 				</form>
 			</div>
 		</div>