fix(neovim): SQL support fixed

- fix: Old completion plugin removed
- refactor: All DADBOD plugins & their configs merged
- new: Map <leader>Q to execute query
- LSP: sqlls lsp removed

common/.config/nvim/lsp/sqlls.lua

@@ -1,4 +0,0 @@
-return {
-    cmd = { "sql-language-server", "up", "--method", "stdio" },
-    filetypes = { "sql" },
-}