Allow disable code tab (#20805)

I know some users created a repository in an organization but just use
issues and projects to handle the whole organizations issues. So that
`Code` could be disabled per repository.

<img width="1148" alt="image"
src="https://user-images.githubusercontent.com/81045/184792075-346cb508-b620-4adb-bc9a-cba76fdcb294.png">

It could also become a wiki repository.

<img width="1173" alt="image"
src="https://user-images.githubusercontent.com/81045/184792324-e15c6f68-35c0-4105-ab77-83585ce53672.png">

Co-authored-by: delvh <dev.lh@web.de>

routers/web/repo/setting.go

@@ -397,6 +397,15 @@ func SettingsPost(ctx *context.Context) {
 			repoChanged = true
 		}
 
+		if form.EnableCode && !unit_model.TypeCode.UnitGlobalDisabled() {
+			units = append(units, repo_model.RepoUnit{
+				RepoID: repo.ID,
+				Type:   unit_model.TypeCode,
+			})
+		} else if !unit_model.TypeCode.UnitGlobalDisabled() {
+			deleteUnitTypes = append(deleteUnitTypes, unit_model.TypeCode)
+		}
+
 		if form.EnableWiki && form.EnableExternalWiki && !unit_model.TypeExternalWiki.UnitGlobalDisabled() {
 			if !validation.IsValidExternalURL(form.ExternalWikiURL) {
 				ctx.Flash.Error(ctx.Tr("repo.settings.external_wiki_url_error"))

services/forms/repo_form.go

@@ -134,6 +134,7 @@ type RepoSettingForm struct {
 	EnablePrune            bool
 
 	// Advanced settings
+	EnableCode                            bool
 	EnableWiki                            bool
 	EnableExternalWiki                    bool
 	ExternalWikiURL                       string

templates/repo/settings/options.tmpl

@@ -249,6 +249,19 @@
 				{{.CsrfTokenHtml}}
 				<input type="hidden" name="action" value="advanced">
 
+				{{$isCodeEnabled := .Repository.UnitEnabled $.Context $.UnitTypeCode}}
+				<div class="inline field">
+					<label>{{.locale.Tr "repo.code"}}</label>
+					{{if .UnitTypeCode.UnitGlobalDisabled}}
+					<div class="ui checkbox tooltip disabled" data-content="{{.locale.Tr "repo.unit_disabled"}}">
+					{{else}}
+					<div class="ui checkbox">
+					{{end}}
+						<input class="enable-system" name="enable_code" type="checkbox"{{if $isCodeEnabled}} checked{{end}}>
+						<label>{{.locale.Tr "repo.code.desc"}}</label>
+					</div>
+				</div>
+
 				{{$isWikiEnabled := or (.Repository.UnitEnabled $.Context $.UnitTypeWiki) (.Repository.UnitEnabled $.Context $.UnitTypeExternalWiki)}}
 				<div class="inline field">
 					<label>{{.locale.Tr "repo.wiki"}}</label>