Introduces `<leader>gw` to format the entire buffer using the internal
formatting operator gw. It preserves the current window view (cursor
position and scroll) during the operation.
Also move away from using the telescope builtin grep for word under
cursor mapping by extending the `:Rg` command to work in the following
circumstances:
* `:Rg text to search for`
* `:Rg` word under cursor
* `'<,'>Rg` visual selection
