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

go.mod

@@ -98,7 +98,7 @@ require (
 	github.com/syndtr/goleveldb v1.0.0
 	github.com/tstranex/u2f v1.0.0
 	github.com/ulikunitz/xz v0.5.11
-	github.com/urfave/cli v1.22.14
+	github.com/urfave/cli/v2 v2.25.7
 	github.com/xanzy/go-gitlab v0.86.0
 	github.com/xeipuuv/gojsonschema v1.2.0
 	github.com/yohcop/openid-go v1.0.1
@@ -278,6 +278,7 @@ require (
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	github.com/xi2/xz v0.0.0-20171230120015-48954b6210f8 // indirect
+	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
 	github.com/zeebo/blake3 v0.2.3 // indirect
 	go.etcd.io/bbolt v1.3.7 // indirect
 	go.mongodb.org/mongo-driver v1.12.0 // indirect