Add Cargo package registry (#21888)

This PR implements a [Cargo registry](https://doc.rust-lang.org/cargo/)
to manage Rust packages. This package type was a little bit more
complicated because Cargo needs an additional Git repository to store
its package index.

Screenshots:

![grafik](https://user-images.githubusercontent.com/1666336/203102004-08d812ac-c066-4969-9bda-2fed818554eb.png)

![grafik](https://user-images.githubusercontent.com/1666336/203102141-d9970f14-dca6-4174-b17a-50ba1bd79087.png)

![grafik](https://user-images.githubusercontent.com/1666336/203102244-dc05743b-78b6-4d97-998e-ef76341a978f.png)

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

custom/conf/app.example.ini

@@ -2458,6 +2458,8 @@ ROUTER = console
 ;LIMIT_TOTAL_OWNER_COUNT = -1
 ;; Maximum size of packages a single owner can use (`-1` means no limits, format `1000`, `1 MB`, `1 GiB`)
 ;LIMIT_TOTAL_OWNER_SIZE = -1
+;; Maximum size of a Cargo upload (`-1` means no limits, format `1000`, `1 MB`, `1 GiB`)
+;LIMIT_SIZE_CARGO = -1
 ;; Maximum size of a Composer upload (`-1` means no limits, format `1000`, `1 MB`, `1 GiB`)
 ;LIMIT_SIZE_COMPOSER = -1
 ;; Maximum size of a Conan upload (`-1` means no limits, format `1000`, `1 MB`, `1 GiB`)