Implement actions artifacts (#22738)

Implement action artifacts server api.

This change is used for supporting
https://github.com/actions/upload-artifact and
https://github.com/actions/download-artifact in gitea actions. It can
run sample workflow from doc
https://docs.github.com/en/actions/using-workflows/storing-workflow-data-as-artifacts.
The api design is inspired by
https://github.com/nektos/act/blob/master/pkg/artifacts/server.go and
includes some changes from gitea internal structs and methods.

Actions artifacts contains two parts:

- Gitea server api and storage (this pr implement basic design without
some complex cases supports)
- Runner communicate with gitea server api (in comming)

Old pr https://github.com/go-gitea/gitea/pull/22345 is outdated after
actions merged. I create new pr from main branch.


![897f7694-3e0f-4f7c-bb4b-9936624ead45](https://user-images.githubusercontent.com/2142787/219382371-eb3cf810-e4e0-456b-a8ff-aecc2b1a1032.jpeg)

Add artifacts list in actions workflow page.

models/migrations/v1_20/v257.go

@@ -0,0 +1,33 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_20 //nolint
+
+import (
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/xorm"
+)
+
+func CreateActionArtifactTable(x *xorm.Engine) error {
+	// ActionArtifact is a file that is stored in the artifact storage.
+	type ActionArtifact struct {
+		ID                 int64 `xorm:"pk autoincr"`
+		RunID              int64 `xorm:"index UNIQUE(runid_name)"` // The run id of the artifact
+		RunnerID           int64
+		RepoID             int64 `xorm:"index"`
+		OwnerID            int64
+		CommitSHA          string
+		StoragePath        string             // The path to the artifact in the storage
+		FileSize           int64              // The size of the artifact in bytes
+		FileCompressedSize int64              // The size of the artifact in bytes after gzip compression
+		ContentEncoding    string             // The content encoding of the artifact
+		ArtifactPath       string             // The path to the artifact when runner uploads it
+		ArtifactName       string             `xorm:"UNIQUE(runid_name)"` // The name of the artifact when runner uploads it
+		Status             int64              `xorm:"index"`              // The status of the artifact
+		CreatedUnix        timeutil.TimeStamp `xorm:"created"`
+		UpdatedUnix        timeutil.TimeStamp `xorm:"updated index"`
+	}
+
+	return x.Sync(new(ActionArtifact))
+}