pyenv support

[cr-mitmit]

Support for pyenv right prompt

Introduce _tide_item_pyenv.fish which extracts pyenv version python projects if pyenv is installed on machine

Motivation and Context

Closes #

Screenshots (if appropriate)

How Has This Been Tested

• [ ] I have tested using Linux.
• [ v] I have tested using MacOS.

Checklist

• [ ] I have updated the documentation accordingly.
• [ ] I have updated the tests accordingly.