Refactor to use urfave/cli/v2 (#25959)

Replace #10912

And there are many new tests to cover the CLI behavior

There were some concerns about the "option order in hook scripts"
(https://github.com/go-gitea/gitea/pull/10912#issuecomment-1137543314),
it's not a problem now. Because the hook script uses `/gitea hook
--config=/app.ini pre-receive` format. The "config" is a global option,
it can appear anywhere.

----

## ⚠️ BREAKING ⚠️

This PR does it best to avoid breaking anything. The major changes are:

* `gitea` itself won't accept web's options: `--install-port` / `--pid`
/ `--port` / `--quiet` / `--verbose` .... They are `web` sub-command's
options.
    * Use `./gitea web --pid ....` instead
* `./gitea` can still run the `web` sub-command as shorthand, with
default options
* The sub-command's options must follow the sub-command
* Before: `./gitea --sub-opt subcmd` might equal to `./gitea subcmd
--sub-opt` (well, might not ...)
    * After: only `./gitea subcmd --sub-opt` could be used
    * The global options like `--config` are not affected

cmd/admin_user_must_change_password.go

@@ -9,23 +9,25 @@ import (
 
 	user_model "code.gitea.io/gitea/models/user"
 
-	"github.com/urfave/cli"
+	"github.com/urfave/cli/v2"
 )
 
-var microcmdUserMustChangePassword = cli.Command{
+var microcmdUserMustChangePassword = &cli.Command{
 	Name:   "must-change-password",
 	Usage:  "Set the must change password flag for the provided users or all users",
 	Action: runMustChangePassword,
 	Flags: []cli.Flag{
-		cli.BoolFlag{
-			Name:  "all,A",
-			Usage: "All users must change password, except those explicitly excluded with --exclude",
+		&cli.BoolFlag{
+			Name:    "all",
+			Aliases: []string{"A"},
+			Usage:   "All users must change password, except those explicitly excluded with --exclude",
 		},
-		cli.StringSliceFlag{
-			Name:  "exclude,e",
-			Usage: "Do not change the must-change-password flag for these users",
+		&cli.StringSliceFlag{
+			Name:    "exclude",
+			Aliases: []string{"e"},
+			Usage:   "Do not change the must-change-password flag for these users",
 		},
-		cli.BoolFlag{
+		&cli.BoolFlag{
 			Name:  "unset",
 			Usage: "Instead of setting the must-change-password flag, unset it",
 		},
@@ -48,7 +50,7 @@ func runMustChangePassword(c *cli.Context) error {
 		return err
 	}
 
-	n, err := user_model.SetMustChangePassword(ctx, all, mustChangePassword, c.Args(), exclude)
+	n, err := user_model.SetMustChangePassword(ctx, all, mustChangePassword, c.Args().Slice(), exclude)
 	if err != nil {
 		return err
 	}