Multi-workspace doesn't display correct python interpreter if a file that's open is different from the root

[rchiodo]

Steps to reproduce:

1. Open multi workspace
2. Open two files from two different folders
3. Set python interpreter to be different for each
4. Close workspace
5. Reopen

One of the files will show the wrong interpreter (might have to switch which one is active by default to get it to repro)

[karrtikr]

Bug is in line 158 of extension.ts .

    interpreterManager.refresh(workspaceService.hasWorkspaceFolders ? workspaceService.workspaceFolders![0].uri : undefined)
        .catch(ex => console.error('Python Extension: interpreterManager.refresh', ex));

When the workspace is reopened, the extension is told to always use the first workspace folder workspaceService.workspaceFolders![0].uri to refresh interpreters instead of using the "Active resource" to get the workspace folder.

The following code in activationManager.ts provides that.

    private getActiveResource(): Resource {
        if (this.documentManager.activeTextEditor && !this.documentManager.activeTextEditor.document.isUntitled) {
            return this.documentManager.activeTextEditor.document.uri;
        }
        return Array.isArray(this.workspaceService.workspaceFolders) && workspace.workspaceFolders!.length > 0
            ? workspace.workspaceFolders![0].uri
            : undefined;
    }

[kimadeline]

✅ Works now:

first venv (opened by default)	second venv	third venv