Reflactor about lspui.nvim HOT 3 CLOSED

Development specification:

1. Each module contains its own init function
2. Create command when module init
3. Each module is decoupled, can be referenced and used separately
4. Each module has func run
5. As neovim is the host system, its plugins should be kept as minimally intrusive as possible

from lspui.nvim.

In feature, maybe some nvim-builtin func need to be rewrite ?
such as get next diagnostic, it do repeated operations

from lspui.nvim.

now, I didn't know how to display callHierarchy

from lspui.nvim.