Resolved Environments have an invalid type for workspaceFolder

[DonJayamanne]

When using the Python Extension API, the resolve Enviornments have an incorrect type for the property workspaceFolder.
workspaceFolder is not a Uri object, but a regular Object.

I've looked at the code, the problem is the fact that enviornments are serialized into JSON and then restored back again when storing from/into the memento.

Note: Objects with Uris cannot be stored in Memento nor can they be serialized into JSON and then parsed back

https://github.com/DonJayamanne/pythonVSCode/blob/main/src/client/pythonEnvironments/base/locators/composite/envsCollectionCache.ts#L186

This is causing issues in the Python extension and new environments are not geting picked up because we're now filtering these enviornments based on the workspace Folder, however since the worksapceFolder isn't a Uri object the conditions fail and as a result new Python virtual envoirnments end up getting excluded in Jupyter extension.

[karthiknadig]

@DonJayamanne this is my proposal to address this issue.

The Cause: The workspaceFolder field is set using an internal field searchLocation. searchLocation is what gets saved to Memento as Uri. when we read it back it looks like this:

Interim Solution:

• Reading (broken case): Since there are already existing cases where this is broken. The surgical fix is to read bad value, extract the scheme and path, use that to re-create the URI.
• Reading/Writing (new case): Make sure that we convert Uri to string before writing and parse back the Uri when reading.

Long term solution:
Object written to memento needs to be serialized using a custom serializer that validates all values before writing and after reading.