feat: support auto-updating fortls in conda environments

[emanspeaks]

Is there an existing request for this?

• I have searched the existing issues

I have tried the Pre-Release of the extension.

• Feature is not present in the latest Pre-Release

Feature Request

Discussions at fortran-lang/fortls#346 and https://fortran-lang.discourse.group/t/auto-updating-packages-and-package-managers-fortls/7115 concluded that fortls should not be self-updating, at least in the sense that it is out of scope for a language server. However, there is still desire to have a capability somewhere to support autoupdating for those users who seek this feature. Perhaps it is more appropriate as a feature in this extension since it could be seen as the overall environment manager for the server's usage in VSCode.