Fix add authentication page (#16543)

* Fix add authentication page

There is a regression in #16199 whereby the add authentication page
fails to react to the change in selected type.

This is due to the String() method on the LoginSourceType which is ameliorated
with an Int() function being added.

Following on from this there are a few other related bugs.

Fix #16541

Signed-off-by: Andrew Thornton <art27@cantab.net>

templates/admin/auth/new.tmpl

@@ -13,12 +13,12 @@
 				<div class="inline required field {{if .Err_Type}}error{{end}}">
 					<label>{{.i18n.Tr "admin.auths.auth_type"}}</label>
 					<div class="ui selection type dropdown">
-						<input type="hidden" id="auth_type" name="type" value="{{.type}}">
+						<input type="hidden" id="auth_type" name="type" value="{{.type.Int}}">
 						<div class="text">{{.CurrentTypeName}}</div>
 						{{svg "octicon-triangle-down" 14 "dropdown icon"}}
 						<div class="menu">
 							{{range .AuthSources}}
-								<div class="item" data-value="{{.Type}}">{{.Name}}</div>
+								<div class="item" data-value="{{.Type.Int}}">{{.Name}}</div>
 							{{end}}
 						</div>
 					</div>