Move global pm commands into a separate `vp global` command

[liangmiQwQ]

Description

Vite+ has an own global package management logic, it's designed mainly for global binaries to deal with different node versions.

Now, It uses vp [pm] -g as the entry, but considering vp [pm] without -g delegates commands to underlying package manager, it sometimes makes users confused.

For example, in #1644, the reason why vp link linked package does not appear in the vp list -g output is just related to the problems above.

Suggested solution

Yarn's global package management might be a model worth learning from. Different from most pms, yarn does not -g flag such as yarn install -g vue to mark global installation; instead, it implemented a separate yarn global update/install command.

For Vite+, we can also use this command style. Make vp global used to manage Vite+'s global packages, and keep vp [commands] -g using underlying package managers with a confirm prompt / warn¹.

Additional context

This issue is reference from #1644 (comment) and #1644 (comment). It can also help decide #1621 as it makes vp global a separate concept.

Footnotes

1. If vp global command is an acceptable solution here, how to process vp [commands] -g there may be worth discussing.** ↩