Support configuration variables on Gitea Actions (#24724)

Co-Author: @silverwind @wxiaoguang 
Replace: #24404

See:
- [defining configuration variables for multiple
workflows](https://docs.github.com/en/actions/learn-github-actions/variables#defining-configuration-variables-for-multiple-workflows)
- [vars
context](https://docs.github.com/en/actions/learn-github-actions/contexts#vars-context)

Related to:
- [x] protocol: https://gitea.com/gitea/actions-proto-def/pulls/7
- [x] act_runner: https://gitea.com/gitea/act_runner/pulls/157
- [x] act: https://gitea.com/gitea/act/pulls/43

#### Screenshoot
Create Variable:

![image](https://user-images.githubusercontent.com/33891828/236758288-032b7f64-44e7-48ea-b07d-de8b8b0e3729.png)


![image](https://user-images.githubusercontent.com/33891828/236758174-5203f64c-1d0e-4737-a5b0-62061dee86f8.png)

Workflow:
```yaml
  test_vars:
    runs-on: ubuntu-latest
    steps:
      - name: Print Custom Variables
        run: echo "${{ vars.test_key }}"
      - name: Try to print a non-exist var
        run: echo "${{ vars.NON_EXIST_VAR }}"
```

Actions Log:

![image](https://user-images.githubusercontent.com/33891828/236759075-af0c5950-368d-4758-a8ac-47a96e43b6e2.png)

---
This PR just implement the org / user (depends on the owner of the
current repository) and repo level variables, The Environment level
variables have not been implemented.
Because
[Environment](https://docs.github.com/en/actions/deployment/targeting-different-environments/using-environments-for-deployment#about-environments)
is a module separate from `Actions`. Maybe it would be better to create
a new PR to do it.

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>

routers/web/shared/secrets/secrets.go

@@ -4,14 +4,12 @@
 package secrets
 
 import (
-	"net/http"
-	"strings"
-
 	"code.gitea.io/gitea/models/db"
 	secret_model "code.gitea.io/gitea/models/secret"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/web"
+	"code.gitea.io/gitea/routers/web/shared/actions"
 	"code.gitea.io/gitea/services/forms"
 )
 
@@ -28,23 +26,20 @@ func SetSecretsContext(ctx *context.Context, ownerID, repoID int64) {
 func PerformSecretsPost(ctx *context.Context, ownerID, repoID int64, redirectURL string) {
 	form := web.GetForm(ctx).(*forms.AddSecretForm)
 
-	content := form.Content
-	// Since the content is from a form which is a textarea, the line endings are \r\n.
-	// It's a standard behavior of HTML.
-	// But we want to store them as \n like what GitHub does.
-	// And users are unlikely to really need to keep the \r.
-	// Other than this, we should respect the original content, even leading or trailing spaces.
-	content = strings.ReplaceAll(content, "\r\n", "\n")
-
-	s, err := secret_model.InsertEncryptedSecret(ctx, ownerID, repoID, form.Title, content)
-	if err != nil {
-		log.Error("InsertEncryptedSecret: %v", err)
-		ctx.Flash.Error(ctx.Tr("secrets.creation.failed"))
-	} else {
-		ctx.Flash.Success(ctx.Tr("secrets.creation.success", s.Name))
+	if err := actions.NameRegexMatch(form.Name); err != nil {
+		ctx.JSONError(ctx.Tr("secrets.creation.failed"))
+		return
 	}
 
-	ctx.Redirect(redirectURL)
+	s, err := secret_model.InsertEncryptedSecret(ctx, ownerID, repoID, form.Name, actions.ReserveLineBreakForTextarea(form.Data))
+	if err != nil {
+		log.Error("InsertEncryptedSecret: %v", err)
+		ctx.JSONError(ctx.Tr("secrets.creation.failed"))
+		return
+	}
+
+	ctx.Flash.Success(ctx.Tr("secrets.creation.success", s.Name))
+	ctx.JSONRedirect(redirectURL)
 }
 
 func PerformSecretsDelete(ctx *context.Context, ownerID, repoID int64, redirectURL string) {
@@ -52,12 +47,9 @@ func PerformSecretsDelete(ctx *context.Context, ownerID, repoID int64, redirectU
 
 	if _, err := db.DeleteByBean(ctx, &secret_model.Secret{ID: id, OwnerID: ownerID, RepoID: repoID}); err != nil {
 		log.Error("Delete secret %d failed: %v", id, err)
-		ctx.Flash.Error(ctx.Tr("secrets.deletion.failed"))
-	} else {
-		ctx.Flash.Success(ctx.Tr("secrets.deletion.success"))
+		ctx.JSONError(ctx.Tr("secrets.deletion.failed"))
+		return
 	}
-
-	ctx.JSON(http.StatusOK, map[string]interface{}{
-		"redirect": redirectURL,
-	})
+	ctx.Flash.Success(ctx.Tr("secrets.deletion.success"))
+	ctx.JSONRedirect(redirectURL)
 }