fix(grug-far-nvim): escape spaces and special symbols in filepath

[azdanov]

📑 Description

I noticed accidentally that when using sf the prefilled path had unescaped spaces, which grug-far didn't seem to support.

To reproduce the issue, try to use it in a path with spaces: e.g. ~/projects/My Demo/readme.md which should be ~/projects/My\ Demo/readme.md for grug-far to work.

ℹ Additional Information

I think https://neovim.io/doc/user/builtin.html#fnameescape() is a way to escape the filepath. But not sure.

[github-actions]

Review Checklist

Does this PR follow the [Contribution Guidelines](development guidelines)? Following is a partial checklist:

Proper conventional commit scoping:

• If you are adding a new plugin, the scope would be the name of the category it is being added into. ex. feat(utility): added noice.nvim plugin

• If you are modifying a pre-existing plugin or pack, the scope would be the name of the plugin folder. ex. fix(noice-nvim): fix LSP handler error

• Pull request title has the appropriate conventional commit type and scope where the scope is the name of the pre-existing directory in the project as described above

• README is properly formatted and uses fenced in links with <url> unless they are inside a [title](url)

• Entry returns a single plugin spec with the new plugin as the only top level spec (not applicable for recipes or packs).

• Proper usage of opts table rather than setting things up with the config function.

• Proper usage of specs table for all specs that are not dependencies of a given plugin (not applicable for recipes or packs).