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/doctor.go

@@ -18,57 +18,58 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 
-	"github.com/urfave/cli"
+	"github.com/urfave/cli/v2"
 	"xorm.io/xorm"
 )
 
 // CmdDoctor represents the available doctor sub-command.
-var CmdDoctor = cli.Command{
+var CmdDoctor = &cli.Command{
 	Name:        "doctor",
 	Usage:       "Diagnose and optionally fix problems",
 	Description: "A command to diagnose problems with the current Gitea instance according to the given configuration. Some problems can optionally be fixed by modifying the database or data storage.",
 	Action:      runDoctor,
 	Flags: []cli.Flag{
-		cli.BoolFlag{
+		&cli.BoolFlag{
 			Name:  "list",
 			Usage: "List the available checks",
 		},
-		cli.BoolFlag{
+		&cli.BoolFlag{
 			Name:  "default",
 			Usage: "Run the default checks (if neither --run or --all is set, this is the default behaviour)",
 		},
-		cli.StringSliceFlag{
+		&cli.StringSliceFlag{
 			Name:  "run",
 			Usage: "Run the provided checks - (if --default is set, the default checks will also run)",
 		},
-		cli.BoolFlag{
+		&cli.BoolFlag{
 			Name:  "all",
 			Usage: "Run all the available checks",
 		},
-		cli.BoolFlag{
+		&cli.BoolFlag{
 			Name:  "fix",
 			Usage: "Automatically fix what we can",
 		},
-		cli.StringFlag{
+		&cli.StringFlag{
 			Name:  "log-file",
 			Usage: `Name of the log file (default: "doctor.log"). Set to "-" to output to stdout, set to "" to disable`,
 		},
-		cli.BoolFlag{
-			Name:  "color, H",
-			Usage: "Use color for outputted information",
+		&cli.BoolFlag{
+			Name:    "color",
+			Aliases: []string{"H"},
+			Usage:   "Use color for outputted information",
 		},
 	},
-	Subcommands: []cli.Command{
+	Subcommands: []*cli.Command{
 		cmdRecreateTable,
 	},
 }
 
-var cmdRecreateTable = cli.Command{
+var cmdRecreateTable = &cli.Command{
 	Name:      "recreate-table",
 	Usage:     "Recreate tables from XORM definitions and copy the data.",
 	ArgsUsage: "[TABLE]... : (TABLEs to recreate - leave blank for all)",
 	Flags: []cli.Flag{
-		cli.BoolFlag{
+		&cli.BoolFlag{
 			Name:  "debug",
 			Usage: "Print SQL commands sent",
 		},