Improve UX for users looking to replace the movie files in their submissions (#1994)

* Minor refactor to `Submissions.EditModel.OnPost`

and add a message for if client-side validation is skipped

* Improve UX for users looking to replace the movie files in their submissions

* Revert "Improve UX for users looking to replace the movie files in their submissions"

This reverts commit 070b9ff.

* Revert "Minor refactor to `Submissions.EditModel.OnPost`"

This reverts commit f8db086.

* Add a notice (system page) to the submission edit form

Author: YoshiRulz

TASVideos/Constants.cs

@@ -19,6 +19,7 @@ public static class SystemWiki
 	public const string ActivitySummary = "System/ActivitySummary";
 	public const string AvatarRequirements = "System/AvatarRequirements";
 	public const string ClassEditingHelp = "System/ClassEditingHelp";
+	public const string EditMovieHeader = "System/EditMovieHeader";
 	public const string EmailConfirmationSentMessage = "System/EmailConfirmationSentMessage";
 	public const string Error = "System/Error";
 	public const string FilesEditingHelp = "System/FilesEditingHelp";

TASVideos/Pages/Submissions/Edit.cshtml

@@ -5,6 +5,9 @@
 	var canEditPublicationClass = User.Has(PermissionTo.JudgeSubmissions)
 		&& Model.AvailableStatuses.Any(s => s == SubmissionStatus.Accepted);
 }
+<info-alert dismissible="true">
+	@await Html.RenderWiki(SystemWiki.EditMovieHeader)
+</info-alert>
 <top-button-bar condition="Model.CanDelete">
 	<a  asp-page="Delete" asp-route-id="@Model.Id" class="btn btn-danger btn-sm">
 		<i class="fa fa-remove"></i> Delete