Move helpers to be prefixed with gt- (#22879)

As discussed in #22847 the helpers in helpers.less need to have a
separate prefix as they are causing conflicts with fomantic styles

This will allow us to have the `.gt-hidden { display:none !important; }`
style that is needed to for the reverted PR.

Of note in doing this I have noticed that there was already a conflict
with at least one chroma style which this PR now avoids.

I've also added in the `gt-hidden` style that matches the tailwind one
and switched the code that needed it to use that.

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

---------

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/repo/blame.tmpl

@@ -1,9 +1,9 @@
 <div class="{{TabSizeClass .Editorconfig .FileName}} non-diff-file-content">
-	<h4 class="file-header ui top attached header df ac sb fw">
-		<div class="file-header-left df ac py-3 pr-4">
+	<h4 class="file-header ui top attached header gt-df gt-ac gt-sb gt-fw">
+		<div class="file-header-left gt-df gt-ac gt-py-3 gt-pr-4">
 			{{template "repo/file_info" .}}
 		</div>
-		<div class="file-header-right file-actions df ac fw">
+		<div class="file-header-right file-actions gt-df gt-ac gt-fw">
 			<div class="ui buttons">
 				<a class="ui tiny button" href="{{$.RawFileLink}}">{{.locale.Tr "repo.file_raw"}}</a>
 				{{if not .IsViewCommit}}
@@ -57,7 +57,7 @@
 								</td>
 							{{end}}
 							<td rel="L{{$row.RowNumber}}" rel="L{{$row.RowNumber}}" class="lines-code blame-code chroma">
-								<code class="code-inner pl-3">{{$row.Code}}</code>
+								<code class="code-inner gt-pl-3">{{$row.Code}}</code>
 							</td>
 						</tr>
 					{{end}}