feat: package manager

[sxyazi]

A part of #914

---

Add a new one to package.toml then install it:

ya pack -a Reledia/glow

# If it's a sub-directory under the repository
ya pack -a yazi-rs/flavors#catppuccin-mocha 

Install all packages configured in package.toml before:

ya pack -i

Upgrade all packages configured in package.toml to the latest commit:

ya pack -u

ya pack -i will use the commit hash locked by the package.toml, and ya pack -u will automatically update the hash to the latest.

If you don't want a certain package to be updated by ya pack -u, you can specify the = qualifier to permanently lock it:

[plugin]
deps = [
  { use = "Reledia/glow", commit = "=536185a" }
]