feat: add Dropbox driver (#4639 close #4590)

Co-authored-by: Andy Hsu <i@nn.ci>

drivers/dropbox/meta.go

@@ -0,0 +1,42 @@
+package dropbox
+
+import (
+	"github.com/alist-org/alist/v3/internal/driver"
+	"github.com/alist-org/alist/v3/internal/op"
+)
+
+const (
+	DefaultClientID = "76lrwrklhdn1icb"
+)
+
+type Addition struct {
+	RefreshToken string `json:"refresh_token" required:"true"`
+	driver.RootPath
+
+	OauthTokenURL string `json:"oauth_token_url" default:"https://api.xhofe.top/alist/dropbox/token"`
+	ClientID      string `json:"client_id" required:"false" help:"Keep it empty if you don't have one"`
+	ClientSecret  string `json:"client_secret" required:"false" help:"Keep it empty if you don't have one"`
+
+	AccessToken string
+}
+
+var config = driver.Config{
+	Name:              "Dropbox",
+	LocalSort:         false,
+	OnlyLocal:         false,
+	OnlyProxy:         false,
+	NoCache:           false,
+	NoUpload:          false,
+	NeedMs:            false,
+	DefaultRoot:       "",
+	NoOverwriteUpload: true,
+}
+
+func init() {
+	op.RegisterDriver(func() driver.Driver {
+		return &Dropbox{
+			base:        "https://api.dropboxapi.com",
+			contentBase: "https://content.dropboxapi.com",
+		}
+	})
+}