Pyenv versions are incorrectly listsed

[DonJayamanne]

All virtual envs under pyenv have the wrong exes listed in the quickpick and python ext API.
The environments under envs are not the ones that should be used, they are internal.

E.g. helloworld virtual env should not be versions/3.9.9/envs/helloworld/bin/python,
instead it should be versions/helloworld/bin/python

Also in the terminal points to the one directly under versions and not in the envs directory

❯ pyenv shell helloworld
❯ python -c "import sys;print(sys.executable)"
/Users/donjayamanne/.pyenv/versions/helloworld/bin/python

[eleanorjboyd]

stale as this now goes through the python environments extension