Refactor initRepoBranchTagSelector to use new init framework (#33776)

Make "initRepoBranchTagSelector" to use new init framework and fix the
abused "js-branch-tag-selector" styles

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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/repo/branch_dropdown.tmpl

@@ -14,7 +14,8 @@
 
 Search "repo/branch_dropdown" in the template directory to find all occurrences.
 */}}
-<div class="js-branch-tag-selector {{if .ContainerClasses}}{{.ContainerClasses}}{{end}}"
+<div class="{{if .ContainerClasses}}{{.ContainerClasses}}{{end}}"
+	data-global-init="initRepoBranchTagSelector"
 	data-text-release-compare="{{ctx.Locale.Tr "repo.release.compare"}}"
 	data-text-branches="{{ctx.Locale.Tr "repo.branches"}}"
 	data-text-tags="{{ctx.Locale.Tr "repo.tags"}}"

templates/repo/release/list.tmpl

@@ -21,6 +21,7 @@
 								{{$compareTarget = $release.Sha1}}
 							{{end}}
 							{{template "repo/branch_dropdown" dict
+								"ContainerClasses" "release-branch-tag-selector"
 								"Repository" $.Repository
 								"ShowTabTags" true
 								"DropdownFixedText" (ctx.Locale.Tr "repo.release.compare")