Add fpm packaging to x.py

[PragmaTwice]

• add fpm packaging subcommand ./x.py package fpm
• add type annotations for all functions
• add --cmake-path to ./x.py build
• remove release workflow and package.sh

[git-hulk]

@PragmaTwice This PR looks good to me and it becomes cleaner that we replace most scripts with x.py, but I'm wondering how we release those binaries after this PR.

[PragmaTwice]

I tried to fix the release workflow and upload packages automatically to a draft release in #751.

@tisonkun suggested that we can directly remove the release workflow and move packaging scripts to x.py.

I do not know whether the release vote process and the release workflow are compatible, maybe we can have a discussion.

[git-hulk]

Thanks @PragmaTwice, sorry that I didn't have a look at the background.

[xiaobiaozhao]

I think rename x.py to build.py is better filename for user.

[PragmaTwice]

I think rename x.py to build.py is better filename for user.

Hi @xiaobiaozhao, this script is versatile for not just build, for example it can execute code inspection tools, package source code, generate rpm packages, etc. (and more and more features are being added) So naming it build.py may not express this meaning well, you can refer to #725 for details.

[PragmaTwice]

Hi @tisonkun, could you take a look at this PR while free?

[tisonkun]

Thanks!