cmd/geth: add db commands stats, compact, put, get, delete (#22014)

This PR introduces:

- db.put to put a value into the database
- db.get to read a value from the database
- db.delete to delete a value from the database
- db.stats to check compaction info from the database
- db.compact to trigger a db compaction

It also moves inspectdb to db.inspect.

internal/flags/helpers.go

@@ -25,7 +25,7 @@ import (
 )
 
 var (
-	CommandHelpTemplate = `{{.cmd.Name}}{{if .cmd.Subcommands}} command{{end}}{{if .cmd.Flags}} [command options]{{end}} [arguments...]
+	CommandHelpTemplate = `{{.cmd.Name}}{{if .cmd.Subcommands}} command{{end}}{{if .cmd.Flags}} [command options]{{end}} {{.cmd.ArgsUsage}}
 {{if .cmd.Description}}{{.cmd.Description}}
 {{end}}{{if .cmd.Subcommands}}
 SUBCOMMANDS:
@@ -36,7 +36,7 @@ SUBCOMMANDS:
 {{end}}
 {{end}}{{end}}`
 
-	OriginCommandHelpTemplate = `{{.Name}}{{if .Subcommands}} command{{end}}{{if .Flags}} [command options]{{end}} [arguments...]
+	OriginCommandHelpTemplate = `{{.Name}}{{if .Subcommands}} command{{end}}{{if .Flags}} [command options]{{end}} {{.ArgsUsage}}
 {{if .Description}}{{.Description}}
 {{end}}{{if .Subcommands}}
 SUBCOMMANDS: