feat: go install option and extracted prev into agnostic function

[AlejandroSuero]

Motivation

I think if the user, uses go, this installation process could be an option.

Benefits

The go option doesn't need maintainability because uses the latest stable package.

Now with the agnostic, it introduces better support for Windows extraction. Previously it will only use tar as extraction method, but now it uses Expand-Archive which is native in powershell.

Note

release_file_url function now also returns the os in case is needed, like in the agnostic_install_glow function, to decide the output_filename and which command to use.
Instead of having to repeat the os logic (could be extracted in another PR if needed, for better reusability).

Test Results

Starting...
Scheduling: tests//glow/glow_spec.lua

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Testing:        /path/to/nvim_plugins/glow.nvim/tests/glow/glow_spec.lua
Success ||      setup setup with default configs
Success ||      setup setup with custom configs

Success:        2
Failed :        0
Errors :        0
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