Enable project wizard in release builds

[sharon-wang]

Intent

• Address Project Wizard: enable New Project functionality in release builds #2878

Approach

• remove the feature flag code fences, so the project wizard is shown by default in both dev builds and release builds
• repurpose the existing configuration setting to instead feature flag WIP project wizard features
• unrelated fix to hide interpreter dropdown feedback when interpreters are still loading
• since the project wizard will be available in release builds, disable the Create button for a new python-based project with Conda, although the dropdown will show when the configuration setting is enabled
• feature flag Conda and renv::init UI, as these are not yet implemented

QA Notes

• the Project Wizard should show in a release build in all your favourite places to open the Project Wizard ✨
• toggle the work-in-progress project wizard features by looking up the setting positron.work-In-ProgressProjectWizardFeatures (looking up "wizard" is probably sufficient)
  
• the work-in-progress project wizard features are:
  • running renv::init for R projects: Project Wizard: create renv::init command #3127
  • using conda as a python environment provider: Project Wizard: Python project environment step - Conda #2839

Local Release Build

For some reason, the updated config setting doesn't always get picked up into the release build. The following steps seem to be necessary:

• ensure you've closed any other instances of Positron
• delete the out* directories (maybe you don't need to delete all of them, but just in case!)
  
• rebuild the release yarn gulp vscode
• your build has the expected changes if you see the setting on the right
  

[sharon-wang]

This is ready for review, but I'm leaving it as a Draft PR while the project wizard issues are being verified, so it doesn't get accidentally merged in the meantime.

[petetronic]

Rebuilt positron for Mac ARM64 locally and confirmed that New Project options were available and the new advanced setting gating work in progress was present and disabled by default. Enabling this exposed the WIP features.

[timtmok]

LGTM