refactor: use telescope/fzf-lua to replace glance.nvim

[ayamir]

This pr removed glance.nvim. Reason:

1. glance.nvim just has vscode like ui, but it's inconvinent for lots of results. Use telescope/fzf-lua is more suitable b/c it can search result.
2. Keymap unify. glance.nvim use v to vsplit, but telescope/fzf-lua use <C-v>.
3. Debloat plugins.

Besides, this pr use Lspsaga peek_definition to preview definition, which will change the keymap to jump to definition in the preview buf (Now is <C-o>), but the spilt-related keymap is consistent with telescope/fzf (<C-v>/<C-x>)