Refactor to new framework (#98)

- Adjust directory structure
```text
├── internal
│   ├── app
│   │   ├── artifactcache
│   │   ├── cmd
│   │   ├── poll
│   │   └── run
│   └── pkg
│       ├── client
│       ├── config
│       ├── envcheck
│       ├── labels
│       ├── report
│       └── ver
└── main.go
```
- New pkg `labels` to parse label
- New pkg `report` to report logs to Gitea
- Remove pkg `engine`, use `envcheck` to check if docker running.
- Rewrite `runtime` to `run`
- Rewrite `poller` to `poll`
- Simplify some code and remove what's useless.

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/98
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Jason Song <i@wolfogre.com>
Co-committed-by: Jason Song <i@wolfogre.com>

internal/app/artifactcache/model.go

@@ -0,0 +1,30 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package artifactcache
+
+import (
+	"fmt"
+	"net/http"
+)
+
+type Cache struct {
+	ID        int64  `xorm:"id pk autoincr" json:"-"`
+	Key       string `xorm:"TEXT index unique(key_version)" json:"key"`
+	Version   string `xorm:"TEXT unique(key_version)" json:"version"`
+	Size      int64  `json:"cacheSize"`
+	Complete  bool   `xorm:"index(complete_used_at)" json:"-"`
+	UsedAt    int64  `xorm:"index(complete_used_at) updated" json:"-"`
+	CreatedAt int64  `xorm:"index created" json:"-"`
+}
+
+// Bind implements render.Binder
+func (c *Cache) Bind(_ *http.Request) error {
+	if c.Key == "" {
+		return fmt.Errorf("missing key")
+	}
+	if c.Version == "" {
+		return fmt.Errorf("missing version")
+	}
+	return nil
+}